Four stable kernel updates

The 6.8.3, 6.7.12, 6.6.24, and 6.1.84 stable kernel updates have beenreleased. Each contains an important set of fixes. Note that 6.7.12 isthe final release for the 6.7.y series, and that branch is nowend-of-life. Users should move to the 6.8.y branch.