Kernel prepatch 6.15-rc1

Linus has released 6.15-rc1 and closed the
merge window for this release. 'As expected, this was one of the bigger
merge windows, almost certainly just because we had some pent-up
development due to the previous releases being impacted by the holiday
season. That said, while it's bigger than normal, it's not some kind of
record-breaking thing.'. In the end, 12.633 non-merge changesets were
pulled into the mainline during this merge window.