- Embedded some test dependencies in MODULE.bazel with use_repo_rule, this avoids loading some .bzl files under src/test when building Bazel (and reduced some boilerplate).
- Use pkg_files from rules_pkg to exclude some sources that are not needed in the bazel distfile (e.g test sources and documentation).

With this change, touching only tests and documentation code should no longer trigger the expensive bootstrap tests.

PiperOrigin-RevId: 698478000
Change-Id: I7fdf49123b6954bab7e5b31795ea657e559bffbe