GitHub Actions updates and improvements for 6.6

[desrosj]

This ticket is for various updates and improvements for Core's GitHub Actions workflows.

Previously:

• 6.5 (#59805)
• 6.4 (#58867)
• 6.3 (#57865)
• 6.2 (#57572)

[desrosj]

In 57795:

Build/Test Tools: Do not run Props Bot for certain actions from forks.

For PRs that originate from forked repositories, pull_request_review and pull_request_review_comment events do not have the permissions necessary to comment on the PR.

This avoids needlessly running the bot when these conditions are met.

Props jorbin, wildworks.
See #60733.

[desrosj]

In 57915:

Build/Test Tools: Include 6.4 and 6.5 in upgrade testing.

This ensures that upgrading from 6.4 and 6.5 to the desired version is actually tested.

See #60733.

[desrosj]

In 58144:

Build/Test Tools: Don’t upload HTML reports to Codecov.

When generating a human readable code coverage report in HTML format, the Codecov action used to fail silently. An error is now being returned, resulting in a workflow failure.

This adds a skip condition to the appropriate steps so the coverage report is only uploaded when a clover format is generated.

See #60733.

[desrosj]

Closing out. I've opened #61564 for the 6.7 cycle.