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/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