Co-authored-by: Issy Long <issyl0@github.com>

Why does Homebrew on Linux recommend that I install to
/home/linuxbrew/.linuxbrew?

Fix `-1` and other flags so they're handled correctly with casks. Use
the "right" exceptions for declaring invalid combinations and change
their parent class so that `--help` is printed nicely too.

Fixes #9033

The way we currently handle @-versioned formulae linking is pretty
labourius:
- it requires extensive use of `link_overwrite` to avoid the `link`
  stage failing on certain install/upgrade scenarios
- we teach people to use `brew link --force` whenever they wish to
  link a versioned formulae when it's pretty obvious what's expected
  in that situation

Instead, let's:
- automatically unlink other versioned formulae when linking a
  versioned formula (either through `brew link` or `install`/`upgrade`
  /`reinstall`)
- notify the user what we've done (with the same messaging as if
  they had run `brew link` manually)

Let's slow down a little on enhancement PRs to give other maintainers
time to give their feedback.

This is mostly self-directed criticism.

- I don't necessarily agree with this, but it's AP style that words with
  four or more letters should start with a capital when in titles.

- I added these all the way back in December 2019 in #6826, but only
  today realised that things have been failing unnoticeably because
  "warning" level exits with status code 0, so doesn't fail CI.
- Upgrading to "error" level will enable us to see the style errors in
  our docs and fix them faster.
- My editor also auto-formatted the YAML to have double quotes instead
  of single.

- Otherwise this surfaces an error and suggests a fix that doesn't match
  Apple's branding.

RuboCop.
`Use the new Ruby 1.9 hash syntax.`

Co-authored-by: Max Eisner <4730112+max-ae@users.noreply.github.com>

- The `sorbet/files.yaml` file was removed in 4382ee9d in favour of more obvious individual type sigils in all files.

cmd/list.rb: --formula, --cask as default TTY:

cmd/list.rb: proper deprecated message on non TTY outputs

update manpage

update zsh completion

updated manpages/brew.1

update tests

return list_casks

list_spec.rb: not output to stderr

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>

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.

Add an opt-out of this behaviour.

Bumps [github-pages](https://github.com/github/pages-gem) from 207 to 208.
- [Release notes](https://github.com/github/pages-gem/releases)
- [Commits](https://github.com/github/pages-gem/compare/v207...v208

)

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