Update dependency bazelbuild/bazel-skylib to latest version
Update dependency bazelbuild/bazel-skylib to latest version

Included changes:

  - bc97abb33eaacfff3c31ba64719817e7a808b20d Move bzl ext (#265)
  - 68acaa5d6aa65e89d99ac775b3d895fea91a3bae Improve inspect_output_dirs_test bin_dir comparison (#267)

BAZEL_SKYLIB_VERSION_REV_ID: bc97abb33eaacfff3c31ba64719817e7a808b20d
Change-Id: I780bad2c31b5a6ca074f762ce03c9f3495b5d54f

google/copybara,google/copybara,google/copybara