Pins mesh-sdk 4a96793 (go/provisions). The assignments read stays while the
sdk's helper still reads plans there (until L6-P3). A watch's expire now
reads as a removed key.
mesh/repo-check head 33d136e70227 merged into trunk 6b3e15042fee — pass: THE CHANGE ALTERS ITS OWN CHECK (merge-check.sh): main's version judged it; the ch…