crypto/tls: add GODEBUG to control max RSA key size

[rolandshoemaker]

tlsmaxrsasize, See http://go.dev/cl/517495.

[rolandshoemaker]

@gopherbot please open backport issues.

[gopherbot]

Backport issue(s) opened: #61966 (for 1.20), #61967 (for 1.21).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://go.dev/wiki/MinorReleases.

[dmitshur]

CL 517495 is submitted. Is there more to do for Go1.22?

[rolandshoemaker]

I don't believe so, I opened this after the fact in order to create backport issues, so it didn't get closed when the CL was submitted (because it was submitted before the issue existed 😅). Can probably be closed.

[dmitshur]

Let's close it to help keep issues that are open actionable, then. Thanks.