runtime: checkdead fires due to suspected race in the Go runtime when GOMAXPROCS=1 on AWS [1.20 backport]

[gopherbot]

@ianlancetaylor requested issue #59600 to be considered for backport to the next 1.20 minor release.

@gopherbot Please open a backport issue to 1.20.

Quoting @SuperQ :

Is it possible to get this bugfix backported to 1.20? It is affecting users of Prometheus monitoring as we default GOMAXPROCS=1 for the node_exporter to reduce problems with data races in the Linux kernel.

[gopherbot]

Change https://go.dev/cl/504395 mentions this issue: [release-branch.go1.20] runtime: resolve checkdead panic by refining startm lock handling in caller context

[gopherbot]

Closed by merging 3db4f81 to release-branch.go1.20.