Dependabot bumps to older versions

[cmbuckley-nhs]

Because there are older releases with higher version numbers, Dependabot will try to bump this action incorrectly.

The workaround is to add the following ignore condition:

ignore:
  - dependency-name: php-actions/phpunit
    versions: ["5", "6", "7", "8", "9"]

v5 and v6 don't have releases/tags, but Dependabot raised PRs for them today, so I've had to ignore those too.

[g105b]

Thank you for bringing this to my attention. This was done when I incorrectly released the action to have parity with PHPUnit's version releases. It made no sense, so I stopped doing that.

I think enough time has passed since this was the case (these past releases are not even compatible with the new version of Github Actions), so I think it would be safe for me to remove the old releases >v5, do you agree?

[g105b]

Removed all releases/tags that are out of order now: https://github.com/php-actions/phpunit/tags

[willryan-stemcell]

@g105b It still does it for some reason, lol