Update quickget releases_rockylinux() grep

[allumik]

Description

Rocky linux version page (https://dl.rockylinux.org/vault/rocky/) has changed, and no releases were listed as a result. This updates the grep to extract the correct version from the new page.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Packaging (updates the packaging)
• Documentation (updates the documentation)

Checklist:

• I have performed a self-review of my code
• I have tested my code in common scenarios and confirmed there are no regressions

[allumik]

Closing as I did not notice this from yesterday... #1735