Update com_github_bazelbuild_buildtools (#142)

github.com/bazelbuild/buildtools/build has made some API changes that
affect Gazelle. This change updates buildtools and ensures Gazelle
remains compatible.

Note that com_github_bazelbuild_buildtools is shadowed by the one
declared in io_bazel_rules_go. The corresponding dependency, along
with the bazel_gazelle dependency in rules_go will be updated after
this change is submitted.
5 files changed