It's always failing with:

```
---------------------------- Captured stdout setup ----------------------------
  Processing c:\users\runneradmin\appdata\local\temp\pytest-of-runneradmin\pytest-0\popen-gw1\venv_world0\third_pkg
    Preparing metadata (setup.py): started
    Preparing metadata (setup.py): finished with status 'done'
  Processing d:\a\coveragepy\coveragepy
    Installing build dependencies: started
    Installing build dependencies: finished with status 'done'
    Getting requirements to build wheel: started
    Getting requirements to build wheel: finished with status 'error'
    error: subprocess-exited-with-error

    × Getting requirements to build wheel did not run successfully.
    │ exit code: 3221226505
    ╰─> [10 lines of output]
        running egg_info
        writing coverage.egg-info\PKG-INFO
        writing dependency_links to coverage.egg-info\dependency_links.txt
        writing entry points to coverage.egg-info\entry_points.txt
        writing requirements to coverage.egg-info\requires.txt
        writing top-level names to coverage.egg-info\top_level.txt
        reading manifest file 'coverage.egg-info\SOURCES.txt'
        reading manifest template 'MANIFEST.in'
        no previously-included directories found matching 'doc\_build'
        no previously-included directories found matching 'doc\_spell'
        [end of output]

    note: This error originates from a subprocess, and is likely not a problem with pip.
  error: subprocess-exited-with-error
```

3221226505 is:

```
<Yhg1s> nedbat: it was killed with SIGKILL. (exit code 3221226505 is -1073740791, which is 'killed with signal 9')
<Yhg1s> (according to os.WIFSIGNALED() and os.WTERMSIG())
```

This patch simplifies attempting to execute the tests again on
failures in CI. It also limits the scope of the tests being rerun to
include only those that failed on the first try. Additionally, it
enables the maximum verbosity so that the retry is more useful for
troubleshooting.

Also, remove the symbolic references in the comments, since dependabot
doesn't update them.

This adds a GHA job that reliably determines if all the required
dependencies have succeeded or not.

It is now in use in aiohttp (and other aio-libs projects), CherryPy,
some of the Ansible repositories, all of the jaraco's projects (like
`setuptools`, `importlib_metadata`), some of hynek's projects, some
PyCQA, PyCA, PyPA and pytest projects, a few AWS Labs projects (to my
surprise).

The story behind this is explained in more detail at
https://github.com/marketplace/actions/alls-green#why.

https://github.com/orgs/community/discussions/33579