Software-6012: OSG-24

[mwestphall]

• Update docs the reference OSG 23 as the latest series to reference OSG 24 instead
• Update docs that compare OSG 3.6 and 23 to compare 23 and 24
• Remove references to OSG 3.6 and EL7 from most docs
• Update docker references to pull from hub.opensciencegrid.org/osg-htc instead of docker.io/opensciencegrid

[brianhlin]

Marking this as do-not-merge since we should hold off on this until the OSG 24 release

[brianhlin]

We'll need to update this table as well https://osg-htc.org/docs/submit/ap-ospool-aup/#access-point-operation-policy

@timtheisen this table looks stale. Can you add it to the HTCSS release checklist to update this table?

[timtheisen]

Wiil do.