Migrate logging warnings to score_cpp_policies

score_cpp_policies and bazel_cpp_toolchains both merged their side already. We're still on toolchains 0.5.4 with the old hardcoded warnings, so bump to 1.0.2, switch to score_cpp_policies 0.1.1 instead of our git_override, and wire up the new warning features.

Start by locating the dependency declarations for bazel_cpp_toolchains and score_cpp_policies, along with the current hardcoded warning configuration. Update the referenced versions and warning features as described, then verify that the repository uses toolchains 1.0.2 and score_cpp_policies 0.1.1 without the git override.

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