Contributions on GitHub getting stuck

[Magnus Ihse Bursie]

I just noticed that there are many PRs on openjdk/jdk that has gotten 
stuck in a Catch 22, due to how our rules and Skara tools work together.

This list, which currently has 24 PRs on it, lists open PRs that neither 
have a "oca" nor a "rfr" label:

https://github.com/pulls?q=is%3Aopen+is%3Apr+draft%3Afalse+repo%3Aopenjdk%2Fjdk+-label%3Arfr+-label%3Aoca+

It seems that this happens when someone creates a PR, gets told to sign 
the OCA, does so, but then still not is a OpenJDK author (of course!) 
and so cannot create a JBS issue. And without a JBS issue number, Skara 
does not move the PR to the RFR state. And without that, no mail is sent 
out. And at least for the PRs in the build category, I was completely 
oblivious to their existence.

Even though we write stuff like "Please talk on the relevant mailing 
lists first" in the User Guide, people assume (rightfully so, I believe) 
that submitting PRs is an acceptable way to contribute. And when told by 
the bots to go sign the OCA and then being told "Nice, you're good to go 
now!", and still nothing happens, this creates bad optics.

At the very least I think Skara should add some message in these cases 
saying explicitly "You need a JBS issue too get this PR reviewed. Please 
ask on the relevant mailing list for sponsorship". And maybe we should 
rethink if we perhaps should not send a mail in any case, at least 
notifying folks that there is an incoming PR that might need guidance.

/Magnus