Tests: Drop redundant project init from RunCMake.PrecompileHeaders cases

The `CMakeLists.txt` file already calls `cmake_minimum_required` and
`project` before including each case's code.
diff --git a/Tests/RunCMake/PrecompileHeaders/DisabledPch.cmake b/Tests/RunCMake/PrecompileHeaders/DisabledPch.cmake
index 59ee14b..18b09c1 100644
--- a/Tests/RunCMake/PrecompileHeaders/DisabledPch.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/DisabledPch.cmake
@@ -1,5 +1,4 @@
-cmake_minimum_required(VERSION 3.15)
-project(DisabledPch C)
+enable_language(C)
 
 add_library(foo foo.c)
 target_include_directories(foo PUBLIC include)
diff --git a/Tests/RunCMake/PrecompileHeaders/PchDebugGenex.cmake b/Tests/RunCMake/PrecompileHeaders/PchDebugGenex.cmake
index 854689f..039a546 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchDebugGenex.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchDebugGenex.cmake
@@ -1,5 +1,4 @@
-cmake_minimum_required(VERSION 3.15)
-project(PchDebugGenex C)
+enable_language(C)
 
 add_library(foo foo.c)
 target_include_directories(foo PUBLIC include)
diff --git a/Tests/RunCMake/PrecompileHeaders/PchIncludedAllLanguages.cmake b/Tests/RunCMake/PrecompileHeaders/PchIncludedAllLanguages.cmake
index a455410..eef189a 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchIncludedAllLanguages.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchIncludedAllLanguages.cmake
@@ -1,5 +1,5 @@
-cmake_minimum_required(VERSION 3.15)
-project(PchIncludedAllLanguages C CXX)
+enable_language(C)
+enable_language(CXX)
 
 if(CMAKE_CXX_COMPILE_OPTIONS_USE_PCH)
   add_definitions(-DHAVE_PCH_SUPPORT)
diff --git a/Tests/RunCMake/PrecompileHeaders/PchIncludedOneLanguage.cmake b/Tests/RunCMake/PrecompileHeaders/PchIncludedOneLanguage.cmake
index dd582ac..6c5e89d 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchIncludedOneLanguage.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchIncludedOneLanguage.cmake
@@ -1,5 +1,5 @@
-cmake_minimum_required(VERSION 3.16)
-project(PchIncludedAllLanguages C CXX)
+enable_language(C)
+enable_language(CXX)
 
 if(CMAKE_CXX_COMPILE_OPTIONS_USE_PCH)
   add_definitions(-DHAVE_PCH_SUPPORT)
diff --git a/Tests/RunCMake/PrecompileHeaders/PchInterface.cmake b/Tests/RunCMake/PrecompileHeaders/PchInterface.cmake
index aab20d8..c031660 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchInterface.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchInterface.cmake
@@ -1,5 +1,4 @@
-cmake_minimum_required(VERSION 3.15)
-project(PchInterface C)
+enable_language(C)
 
 add_library(foo foo.c)
 target_include_directories(foo PUBLIC include)
diff --git a/Tests/RunCMake/PrecompileHeaders/PchLibObjLibExe.cmake b/Tests/RunCMake/PrecompileHeaders/PchLibObjLibExe.cmake
index b4fdb71..ad8a328 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchLibObjLibExe.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchLibObjLibExe.cmake
@@ -1,5 +1,4 @@
-cmake_minimum_required(VERSION 3.16)
-project(PchLibObjLibExe CXX)
+enable_language(CXX)
 
 foreach(i 1 2 3)
     file(WRITE ${CMAKE_BINARY_DIR}/empty${i}.cpp "void nothing${i}() {}\n")
diff --git a/Tests/RunCMake/PrecompileHeaders/PchMultilanguage.cmake b/Tests/RunCMake/PrecompileHeaders/PchMultilanguage.cmake
index bb18a64..d8abf8e 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchMultilanguage.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchMultilanguage.cmake
@@ -1,5 +1,5 @@
-cmake_minimum_required(VERSION 3.15)
-project(PchMultilanguage C CXX)
+enable_language(C)
+enable_language(CXX)
 
 add_executable(foobar
   foo.c
diff --git a/Tests/RunCMake/PrecompileHeaders/PchPrologueEpilogue.cmake b/Tests/RunCMake/PrecompileHeaders/PchPrologueEpilogue.cmake
index 3e27620..988c4c6 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchPrologueEpilogue.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchPrologueEpilogue.cmake
@@ -1,6 +1,5 @@
-cmake_minimum_required(VERSION 3.15)
-
-project(PchPrologueEpilogue)
+enable_language(C)
+enable_language(CXX)
 
 set(CMAKE_INCLUDE_CURRENT_DIR ON)
 
diff --git a/Tests/RunCMake/PrecompileHeaders/PchReuseFrom.cmake b/Tests/RunCMake/PrecompileHeaders/PchReuseFrom.cmake
index f8fba44..8d5e945 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchReuseFrom.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchReuseFrom.cmake
@@ -1,5 +1,4 @@
-cmake_minimum_required(VERSION 3.15)
-project(PchReuseFrom C)
+enable_language(C)
 
 if(CMAKE_C_COMPILE_OPTIONS_USE_PCH)
   add_definitions(-DHAVE_PCH_SUPPORT)
diff --git a/Tests/RunCMake/PrecompileHeaders/PchReuseFromObjLib.cmake b/Tests/RunCMake/PrecompileHeaders/PchReuseFromObjLib.cmake
index ba504a3..510877f 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchReuseFromObjLib.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchReuseFromObjLib.cmake
@@ -1,6 +1,5 @@
-cmake_minimum_required(VERSION 3.18)
-
-project(PchReuseFromObjLib)
+enable_language(C)
+enable_language(CXX)
 
 set(CMAKE_PCH_WARN_INVALID OFF)
 
diff --git a/Tests/RunCMake/PrecompileHeaders/PchReuseFromPrefixed.cmake b/Tests/RunCMake/PrecompileHeaders/PchReuseFromPrefixed.cmake
index e306d8e..14703e3 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchReuseFromPrefixed.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchReuseFromPrefixed.cmake
@@ -1,5 +1,4 @@
-cmake_minimum_required(VERSION 3.15)
-project(PchReuseFromPrefixed C)
+enable_language(C)
 
 if(CMAKE_C_COMPILE_OPTIONS_USE_PCH)
   add_definitions(-DHAVE_PCH_SUPPORT)
diff --git a/Tests/RunCMake/PrecompileHeaders/PchReuseFromSubdir.cmake b/Tests/RunCMake/PrecompileHeaders/PchReuseFromSubdir.cmake
index fff74dc..fefb4ee 100644
--- a/Tests/RunCMake/PrecompileHeaders/PchReuseFromSubdir.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/PchReuseFromSubdir.cmake
@@ -1,5 +1,4 @@
-cmake_minimum_required(VERSION 3.15)
-project(PchReuseFromSubdir C)
+enable_language(C)
 
 add_library(empty empty.c)
 target_precompile_headers(empty PUBLIC
diff --git a/Tests/RunCMake/PrecompileHeaders/SkipPrecompileHeaders.cmake b/Tests/RunCMake/PrecompileHeaders/SkipPrecompileHeaders.cmake
index 49efbfb..7405e65 100644
--- a/Tests/RunCMake/PrecompileHeaders/SkipPrecompileHeaders.cmake
+++ b/Tests/RunCMake/PrecompileHeaders/SkipPrecompileHeaders.cmake
@@ -1,6 +1,5 @@
-cmake_minimum_required(VERSION 3.15)
-
-project(SkipPrecompileHeaders)
+enable_language(C)
+enable_language(CXX)
 
 set(CMAKE_INCLUDE_CURRENT_DIR ON)