dispatch-ci being added to places it shouldn't be

[GuySartorelli]

The dispatch-ci script should not run for workflows (gha-* repos), or for docs - and possible for other things as well.
We should update the script so that:

1. Only repos that should have it are given it
2. It's removed from everything else, if they do have it.

PRs

• ENH Restrict which repos get dispatch-ci #40
• MNT Remove dispatch-ci silverstripe-standards#6
• MNT Remove dispatch-ci markdown-php-codesniffer#8
• FIX Skip running CI on cycle if only a single major gha-dispatch-ci#11

[GuySartorelli]

PRs merged