Add and vendor `rubocop-sorbet` and `sorbet-runtime-stub`.

sorbet: Update RBI files and prune files.yaml.

Autogenerated by [a scheduled GitHub Action](https://github.com/Homebrew/brew/blob/master/.github/workflows/sorbet.yml).

build(deps-dev): bump github-pages from 208 to 209 in /docs

build(deps): bump codecov from 0.2.11 to 0.2.12 in /Library/Homebrew

Bumps [codecov](https://github.com/codecov/codecov-ruby) from 0.2.11 to 0.2.12.
- [Release notes](https://github.com/codecov/codecov-ruby/releases)
- [Changelog](https://github.com/codecov/codecov-ruby/blob/master/CHANGELOG.md)
- [Commits](https://github.com/codecov/codecov-ruby/compare/v0.2.11...v0.2.12

)

Signed-off-by: dependabot[bot] <support@github.com>

Bumps [github-pages](https://github.com/github/pages-gem) from 208 to 209.
- [Release notes](https://github.com/github/pages-gem/releases)
- [Commits](https://github.com/github/pages-gem/compare/v208...v209

)

Signed-off-by: dependabot[bot] <support@github.com>

Fix `dependabot.yml`.

audit: allow Linux checking Homebrew dependencies.

This applies to linuxbrew-core rather than Linux, really.

audit: check versioned dependency conflicts.

We don't want to have a formula depending on e.g. both `python@3.8` and
`python@3.9` in the same dependency tree (generally).

As this isn't a blanket rule: add an allowlist with the expectation that
we'll need to use it.

Update vendored gems.

Reduce shallow clone usage

GitHub has requested we request our usage of shallow clones. As a
result:

- do default to shallow clones on CI
- do not do --shallow-since when setting up new repositories in
  `brew update`
- do not support shallow clones of homebrew-core at all

We may consider in future unshallowing all clones unconditionally.

cask/cmd/info.rb: Fix crash when running `brew cask info --github`

python: do not add main brewed Python site-package to virtualenv

If added, this makes the virtualenv read the main site-package from brewed Python,
and especially makes it read our sitecustomize.py file, which will
modify the sys.executable path.

See the full discussion at:
https://github.com/Homebrew/brew/pull/8873

I also took the opportunity to not include test deps, as these will
be not be installed, so the .pth file should not contains references
to site-packages from test deps.

Previous packages on Linux did already contain the wrong lines in the pth file,
for example:
cat /home/linuxbrew/.linuxbrew/Cellar/aws-google-auth/0.0.36_1/libexec/lib/python3.8/site-packages/homebrew_deps.pth
import site; site.addsitedir('/home/linuxbrew/.linuxbrew/opt/python@3.8/lib/python3.8/site-packages')
import site; site.addsitedir('/home/linuxbrew/.linuxbrew/opt/libxml2/lib/python3.8/site-packages')

This might have caused subtle bugs for some packages but not for others.

Fix running deprecated command in fish completion

Force `brew upgrade` to treat arguments as casks if `--cask` is passed.

Allow all cask options for `brew reinstall` and `brew upgrade`.