[go][cmx] Use deprecated-global-dev

/dev/null is not a directory, and so routing it as it were causes issues
once we fix issues in devfs that allow it to function as a file.

Tested: fx test go-os-test.cm
Tested: fx test go-exec-test.cm
Change-Id: I5ccdc1fdc17bbe37929db11db804f974678bfaaf
Reviewed-on: https://fuchsia-review.googlesource.com/c/third_party/go/+/582981
Reviewed-by: Tamir Duberstein <tamird@google.com>
Reviewed-by: Shai Barack <shayba@google.com>
Commit-Queue: Suraj Malhotra <surajmalhotra@google.com>
diff --git a/meta/go_exec_test.cmx b/meta/go_exec_test.cmx
index b717012..db65687 100644
--- a/meta/go_exec_test.cmx
+++ b/meta/go_exec_test.cmx
@@ -14,10 +14,8 @@
             "bin",
             "lib"
         ],
-        "dev": [
-            "null"
-        ],
         "features": [
+            "deprecated-global-dev",
             "isolated-temp"
         ],
         "services": [
diff --git a/meta/go_os_test.cmx b/meta/go_os_test.cmx
index 17ace76..e20495d 100644
--- a/meta/go_os_test.cmx
+++ b/meta/go_os_test.cmx
@@ -11,10 +11,8 @@
             "bin",
             "lib"
         ],
-        "dev": [
-            "null"
-        ],
         "features": [
+            "deprecated-global-dev",
             "isolated-temp"
         ],
         "services": [