- Muscle memory is a thing, as is relying heavily on one's shell
  history. Now that the Jenkins runners are gone, `brew pull --bottle`
  no longer works. This removes the option. If maintainers are confused,
  they should [look at recent changes to the
  docs](https://docs.brew.sh/Brew-Test-Bot-For-Core-Contributors#bottling),
  or ask in Slack.
- An earlier iteration of this showed a deprecation warning and a link
  to the docs, but when an option no longer physically works it's a bit
  late for deprecation *warnings*.
- This also fixes a `brew style` warning from futher up in the file.

pull: Appease RuboCop

Refactor cask command parsing logic.

pr-pull: don't try to fetch artifacts for a pull request when the changed formulae don't use bottles

docs: Update for new pr-* workflows

Revert "ENV/std: withdraw support for Homebrew supplied *.pc files"

Ensure TMPDIR is set for Xcode’s `make`

This fixes an issue where at least in Xcode 11.0, `make` uses
`/var/tmp` as a fallback for temporary files unless `TMPDIR` is set:

```
$ strings "$(xcrun -f make)" | grep -B 3 fopen
TMPDIR
/var/tmp/
GmXXXXXX
fopen (temporary file)
```

Given that Homebrew filtered `TMPDIR`, and the `/var/tmp` directory may
not be writable for non-root users, this would cause Homebrew’s
build environment to error out:

```
$ brew ruby -e 'puts ENV["TMPDIR"]; puts `: | make -f -`'
```

```
Ignoring bigdecimal-2.0.0 because its extensions are not built. Try: gem pristine bigdecimal --version 2.0.0
[…]
Ignoring zlib-1.1.0 because its extensions are not built. Try: gem pristine zlib --version 1.1.0
make: *** fopen (temporary file): Permission denied.  Stop.
```

In practice, this would break `brew audit`, `brew style`, and other
commands, which would run `make` to build native gem extensions.

This commit sets `TMPDIR` to `${HOMEBREW_TEMP}` in the gem environment, which
mirrors the behaviour we already have in other places.
We choose `HOMEBREW_TEMP` because that’s user-controlled but also falls
back to `/tmp` in case `TMPDIR` is not set in the user’s environment.

Thanks to Bo Anderson for helping find the bug.

CC: Bo Anderson <mail@boanderson.me>

This reverts commit fa359168.

Improve spec helper.

ENV/super: don't set PKG_CONFIG

env_config: standardize wording, fix some typos

os/mac/xcode: better document upgrade.

Explain when these various versions should (and should not) be bumped
and provide a method to avoid people having to schlep through the Apple
Developer site unless they really want to.

Also, while we're here, DRY things up and reorder to "newest first".

Revert "Set HOMEBREW_GITHUB_API_TOKEN from GITHUB_TOKEN."

ENV/std: restore original make_jobs return type

dev-cmd/pr-publish: fix undefined method error on invalid input

Audit: allow make check for nettle

docs/Formula-Cookbook.md: mention the use of 'bottle :unneeded'

shims/mac/super/xcrun: unset rather than emptying DEVELOPER_DIR

Co-Authored-By: Mike McQuaid <mike@mikemcquaid.com>

formula: make CMake SDK root choice consistent with superenv (+ SDK root refactoring)