Add support for Bzlmod for the next release

https://bazel.build/external/overview#bzlmod

Bzlmod will be the default in a future Bazel release.
By default it requires projects to be registered with the
Bazel Central Registry (https://registry.bazel.build/) and
thus uses regular releases by default.

Users that want to "live-at-head" can still do this through
with overrides (https://bazel.build/external/module#overrides).

This change updates GoogleTest dependencies to use released versions.
CI uses Bzlmod except in the case of linux_gcc-floor, which will
keep testing the old WORKSPACE-based dependency system.

PiperOrigin-RevId: 601489729
Change-Id: I6be52034eba0d0e5fe12110e5e82879305cf73ff

ci/linux-presubmit.sh

@@ -67,6 +67,9 @@ for cc in /usr/local/bin/gcc /opt/llvm/clang/bin/clang; do
 done
 
 # Do one test with an older version of GCC
+# TODO(googletest-team): This currently uses Bazel 5. When upgrading to a
+# version of Bazel that supports Bzlmod, add --enable_bzlmod=false to keep test
+# coverage for the old WORKSPACE dependency management.
 time docker run \
   --volume="${GTEST_ROOT}:/src:ro" \
   --workdir="/src" \
@@ -101,7 +104,7 @@ for std in ${STD}; do
         --copt="-Wuninitialized" \
         --copt="-Wundef" \
         --define="absl=${absl}" \
-        --enable_bzlmod=false \
+        --enable_bzlmod=true \
         --features=external_include_paths \
         --keep_going \
         --show_timestamps \
@@ -126,7 +129,7 @@ for std in ${STD}; do
         --copt="-Wuninitialized" \
         --copt="-Wundef" \
         --define="absl=${absl}" \
-        --enable_bzlmod=false \
+        --enable_bzlmod=true \
         --features=external_include_paths \
         --keep_going \
         --linkopt="--gcc-toolchain=/usr/local" \

ci/macos-presubmit.sh

@@ -69,6 +69,7 @@ for absl in 0 1; do
     --copt="-Wundef" \
     --cxxopt="-std=c++14" \
     --define="absl=${absl}" \
+    --enable_bzlmod=true \
     --features=external_include_paths \
     --keep_going \
     --show_timestamps \

ci/windows-presubmit.bat

@@ -51,6 +51,7 @@ SET BAZEL_VS=C:\Program Files\Microsoft Visual Studio\2022\Community
   --compilation_mode=dbg ^
   --copt=/std:c++14 ^
   --copt=/WX ^
+  --enable_bzlmod=true ^
   --keep_going ^
   --test_output=errors ^
   --test_tag_filters=-no_test_msvc2017