Change databinding dependent lib artifact to a directory

[arunkumar9t2]

Dependent lib artifact is supposed to be a directory but was registered as a file. This is an error in Bazel 7 due to --incompatible_disallow_unsound_directory_outputs which will be enforced in Bazel 8.

Ref

Bazel needs to know whether an artifact is a file or a directory before its contents are produced, and coverage.dat is declared as a file. Before Bazel 7, producing a directory where a file is expected was tolerated, but broken in subtle ways. Bazel 7 forbids it by default (--incompatible_disallow_unsound_directory_outputs) and Bazel 8 will not allow it at all.