I wanted to check the earliest release tag associated with a commit on github but I dont know what do these tags actually mean on the commit description page?
The tags listed there are the tags which contain this commit. The latest one is on the left. This is so that people can tell what versions a commit that fixed their problem is included in. This can be determined with a clone of the repository, but this is simpler than performing a full clone for that purpose.
In this case, it probably means that the commit was first included in 2.13.0.