Tags are back

I just added the tag 2025-07-03 to this repo. The reason is that in the TangoSourceDistribution I'm cloning sub-projects. But I can only clone branches/tags with older git versions, only recent versions 2.49 and above support --revision= to clone arbitrary versions. Other workarounds are IMHO to tedious.

I'll be disabling the tag in readthedocs.