Needed to use dev dependencies in BCR presubmit.

https://buildkite.com/bazel/bcr-presubmit/builds/10562

Signed-off-by: Brentley Jones <github@brentleyjones.com>

This is something I could use in my codebase. I would like have a way to
propagate the `-w` flag to all clang-using targets, and specifically,
selectively disable it in my REPO.bazel and individual targets. This
would allow me to globally suppress warnings for external repositories,
without enabling it in my own code, and without needing to juggle the
state of the flag setting (`-w` and other diagnostic flags are mutually
exclusive afaik). This is the same as how we organize the
`treat_warnings_as_errors` feature today.

Companion change in rules_swift is bazelbuild/rules_swift#1489

This feature is used in bazel to disable anything related to .d files.
This is off by default but must be here to be enabled.

I think this is some legacy workaround

Sidestep #371 until
it's fixed in Xcode. Users who still want this vs can pass
`--linkopt=-Os`

This reverts commit 27df79d.