🔧 optimize CI runs

[ctcpip]

eliminate duplicate runs on PRs

[ljharb]

I'd left it this way intentionally, since it's not a given that a pushed branch will immediately be turned into a PR. The runs are also parallelized, so this won't make full runs any faster, it'll just save github some money.

[michaelficarra]

Do people look at actions status for commits that aren't part of some PR? I'd think this would be a waste somewhere between 99% and 100% of the time.

[ljharb]

I do, but either way it's only a waste for github ¯\_(ツ)_/¯

[ctcpip]

it's not a given that a pushed branch will immediately be turned into a PR

do we really care about pushed non-default branches running CI right away? either they will get a PR, or they will get merged to main without a PR and if that happens, it's likely nobody was looking at the CI result anyway

it's not a big deal either way, but I have my preference 😄

[ljharb]

Most of the time, no, we won't care - but this PR won't improve anything for anyone either, except GitHub :-)

[michaelficarra]

I'm okay with improving things for GitHub.