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

MODULE.bazel

@@ -0,0 +1,57 @@
+# Copyright 2024 Google Inc.
+# All Rights Reserved.
+#
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# https://bazel.build/external/overview#bzlmod
+
+module(
+    name = "googletest",
+    version = "head",
+    compatibility_level = 1,
+)
+
+# Only direct dependencies need to be listed below.
+# Please keep the versions in sync with the versions in the WORKSPACE file.
+
+bazel_dep(name = "abseil-cpp",
+          version = "20240116.0",
+          repo_name = "com_google_absl")
+
+bazel_dep(name = "platforms",
+          version = "0.0.8")
+
+bazel_dep(name = "re2",
+          repo_name = "com_googlesource_code_re2",
+          version = "2023-11-01")
+
+bazel_dep(name = "rules_python",
+          version = "0.29.0")
+
+# https://github.com/bazelbuild/rules_python/blob/main/BZLMOD_SUPPORT.md#default-toolchain-is-not-the-local-system-python
+register_toolchains("@bazel_tools//tools/python:autodetecting_toolchain")