gitlab-ci: Move macOS+Xcode universal binaries job to arm64

Over time we are adding `arm64` hosts and removing `x86_64` hosts.
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 82abb44..305c8d2 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -938,17 +938,17 @@
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
 
-t:macos-x86_64-xcode-ub:
+t:macos-arm64-xcode-ub:
     extends:
-        - .macos_x86_64_xcode_ub
+        - .macos_arm64_xcode_ub
         - .cmake_test_macos_external
-        - .macos_x86_64_tags_ext
+        - .macos_arm64_tags_ext
         - .cmake_junit_artifacts
         - .run_dependent
     dependencies:
-        - t:macos-x86_64-ninja
+        - t:macos-arm64-ninja
     needs:
-        - t:macos-x86_64-ninja
+        - t:macos-arm64-ninja
     variables:
         CMAKE_CI_JOB_NIGHTLY: "true"
 
diff --git a/.gitlab/ci/configure_macos_x86_64_xcode_ub.cmake b/.gitlab/ci/configure_macos_arm64_xcode_ub.cmake
similarity index 100%
rename from .gitlab/ci/configure_macos_x86_64_xcode_ub.cmake
rename to .gitlab/ci/configure_macos_arm64_xcode_ub.cmake
diff --git a/.gitlab/ci/env_macos_arm64_xcode_ub.cmake b/.gitlab/ci/env_macos_arm64_xcode_ub.cmake
new file mode 100644
index 0000000..244f088
--- /dev/null
+++ b/.gitlab/ci/env_macos_arm64_xcode_ub.cmake
@@ -0,0 +1 @@
+set(ENV{CMAKE_OSX_ARCHITECTURES} "arm64;x86_64")
diff --git a/.gitlab/ci/env_macos_x86_64_xcode_ub.cmake b/.gitlab/ci/env_macos_x86_64_xcode_ub.cmake
deleted file mode 100644
index 4b5c401..0000000
--- a/.gitlab/ci/env_macos_x86_64_xcode_ub.cmake
+++ /dev/null
@@ -1 +0,0 @@
-set(ENV{CMAKE_OSX_ARCHITECTURES} "x86_64;arm64")
diff --git a/.gitlab/os-macos.yml b/.gitlab/os-macos.yml
index 3e11fd1..1579338 100644
--- a/.gitlab/os-macos.yml
+++ b/.gitlab/os-macos.yml
@@ -80,11 +80,11 @@
         CMAKE_GENERATOR: Xcode
         CMAKE_CI_NIGHTLY_IGNORE_DEPS: "true"
 
-.macos_x86_64_xcode_ub:
+.macos_arm64_xcode_ub:
     extends: .macos
 
     variables:
-        CMAKE_CONFIGURATION: macos_x86_64_xcode_ub
+        CMAKE_CONFIGURATION: macos_arm64_xcode_ub
         CMAKE_GENERATOR: Xcode
         CMAKE_CI_NIGHTLY_IGNORE_DEPS: "true"