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

Included changes:

  - 528e4241345536c487cca8b11db138104bb3bd68 Remove laurentlb from CODEOWNERS (#279)
  - 56ec790c9b881c82e84904705786a9b2b994cb0e Address latent buildifier issues. (#278)

BAZEL_SKYLIB_VERSION_REV_ID: 528e4241345536c487cca8b11db138104bb3bd68
Change-Id: I268b9b21f3afd80b829fb797fae0e9c830ef9b6c

google/copybara,google/copybara,google/copybara