Closes https://github.com/Homebrew/brew/pull/7258

As explained in https://github.com/Homebrew/brew/pull/7256#issuecomment-607787949

Fix regression from https://github.com/Homebrew/brew/pull/7260.

This code makes me sad.

Bumps [tzinfo](https://github.com/tzinfo/tzinfo) from 1.2.6 to 1.2.7.
- [Release notes](https://github.com/tzinfo/tzinfo/releases)
- [Changelog](https://github.com/tzinfo/tzinfo/blob/master/CHANGES.md)
- [Commits](https://github.com/tzinfo/tzinfo/compare/v1.2.6...v1.2.7

)

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

Don't rely on x86_64 detection but instead whitelist the few projects
that fun afoul of these regex.

I tested the workaround with the newest Git and the Catalina system Git
and it wasn't needed in either case. We can re-add it if we get
complaints with supported Git versions.

Fixes https://github.com/Homebrew/brew/issues/7259

Fixes #7250.

Otherwise taps with specs don't get their style fixed.

Bumps [rubocop](https://github.com/rubocop-hq/rubocop) from 0.80.1 to 0.81.0.
- [Release notes](https://github.com/rubocop-hq/rubocop/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop/compare/v0.80.1...v0.81.0

)

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

- This has to be in multiple places, hence a new method. A patch failing
  to apply, which is a common occurrence with HEAD builds because the
  patch is already upstream, raises a different exception to another,
  "normal" build failure.

Tested with:

```
╭─issyl0@rigel /home/linuxbrew/.linuxbrew/Homebrew ‹head-builds-arent-officially-supported*›
╰─ $ brew install --HEAD mtr
==> Cloning https://github.com/traviscross/mtr.git
Updating /home/issyl0/.cache/Homebrew/mtr--git
==> Checking out branch master
Already on 'master'
Your branch is up to date with 'origin/master'.
HEAD is now at 155f76a Merge pull request #340 from Sea-n/master
==> Downloading https://github.com/traviscross/mtr/pull/315.patch?full_index=1
Already downloaded: /home/issyl0/.cache/Homebrew/downloads/82d9d939303d8fceb7a3ae071ecd49a5f075e0fb451b308653b555ffbae74336--315.patch
==> Patching
==> Applying 315.patch
patching file packet/probe.c
Hunk #1 FAILED at 323.
Hunk #2 FAILED at 364.
2 out of 2 hunks FAILED -- saving rejects to file packet/probe.c.rej
Error: Failure while executing; `patch -g 0 -f -p1 -i /tmp/mtr--patch-20200330-10734-avjmyy/315.patch` exited with 1.
HEAD builds are unsupported by maintainers - please file pull requests instead of issues.
```

and

```
╭─issyl0@rigel /home/linuxbrew/.linuxbrew/Homebrew ‹head-builds-arent-officially-supported*›
╰─ $ brew install --HEAD zookeeper
==> Cloning https://gitbox.apache.org/repos/asf/zookeeper.git
Updating /home/issyl0/.cache/Homebrew/zookeeper--git
==> Checking out branch master
Already on 'master'
Your branch is up to date with 'origin/master'.
HEAD is now at 1ff1b779 ZOOKEEPER-3755: Use maven to create fatjar
==> ant compile_jute
Last 15 lines from /home/issyl0/.cache/Homebrew/Logs/zookeeper/01.ant:
2020-03-30 21:45:10 +0100

ant
compile_jute

Picked up _JAVA_OPTIONS: -Duser.home=/home/issyl0/.cache/Homebrew/java_cache
Buildfile: build.xml does not exist!
Build failed

READ THIS: https://docs.brew.sh/Troubleshooting

HEAD builds are unsupported by maintainers - please file pull requests instead of issues.
```

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

Also add debugging statements

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

There appear to be random, seemingly impossible to debug issues with
running integration tests on portable Ruby. Instead of confusing
contributors when these will be run on CI anyway: let's just skip them
by default (like we do with `--online` for online tests anyway).

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

Bumps [unf_ext](https://github.com/knu/ruby-unf_ext) from 0.0.7.6 to 0.0.7.7.
- [Release notes](https://github.com/knu/ruby-unf_ext/releases)
- [Changelog](https://github.com/knu/ruby-unf_ext/blob/master/CHANGELOG.md)
- [Commits](https://github.com/knu/ruby-unf_ext/commits

)

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