Golang runtime: use-after-free of allpSnapshot in findRunnable [1.23 backport]

@prattmic requested issue #74414 to be considered for backport to the next 1.23 minor release.

@gopherbot Please backport to 1.23 and 1.24. This is a long-standing bug, but can cause random crashes when increasing GOMAXPROCS.

Comment From: gopherbot

Change https://go.dev/cl/685075 mentions this issue: [release-branch.go1.23] runtime: stash allpSnapshot on the M

Comment From: gopherbot

Closed by merging CL 685075 (commit 317a3c130e3b59171b3bd90e7a469fba76582444) to release-branch.go1.23.