Pin pybind11_bazel to the same version currently used for pybind11_protobuf.

[copybara-service[bot]]

Pin pybind11_bazel to the same version currently used for pybind11_protobuf.

Leave it for later to resolve the ubuntu-latest bazel failure:

• https://github.com/pybind/pybind11_bazel/issues/94

ERROR: /home/runner/work/pybind11_abseil/pybind11_abseil/pybind11_abseil/tests/BUILD:92:17: Linking pybind11_abseil/tests/missing_import.so failed: (Exit 1): gcc failed: error executing CppLink command (from target //pybind11_abseil/tests:missing_import.so) /usr/bin/gcc @bazel-out/k8-fastbuild/bin/pybind11_abseil/tests/missing_import.so-2.params

Use --sandbox_debug to see verbose messages from the sandbox and retain the sandbox build root for debugging
/usr/bin/ld.gold: undefs: unknown -z option