Inconsistent resolution of 'stable' branch in popup windows

[rouault]

Read the Docs project URL: https://app.readthedocs.org/projects/osgeo-proj/

Recently, the PROJ project has explicitly create a github "stable" branch, instead of relying on the logic of ReadTheDocs that infered "stable" to be the SemVer tag with the higher number, which at time of writing is the 9.5.0 tag. Pushes to that new "stable" branch trigger consistent builds of it. At time of writing, https://app.readthedocs.org/projects/osgeo-proj/builds/ shows

which shows that commit OSGeo/PROJ@8df3845 was built, which correctly refers to the latest HEAD of the 'stable' github branch

So far so good. But if you put your mouse over the "[icon] stable [green tick]" button towards the right of the "Version stable" line, a popup window appears with a "Branch" link whose label is 'stable' but it resolves to https://github.com/OSGeo/PROJ/tree/9.5.0/) as shown in below screenshot:

It seems something in the RTD state hasn't updated the fact that the 'stable' branch exists per se now and is no longer implicitly aliased to the latest SemVer tag 9.5.0

(CC'ing colleagues @hobu and @jjimenezshaw)