CI no longer runs on pushes to main

[nepfaff]

The CI no longer runs if we push to master directly. See ebcda35 for an example.

I see two options:

1. Change the CI to always run on pushes to master
2. Make master a hard protected brunch, forcing even repo admins to create PRs

Option 2 is cleaner. Option 1 is what we have had so far and results in slightly faster development.
@RussTedrake, any preferences?

[RussTedrake]

This is presumable due to #495 . @bernhardpg

[bernhardpg]

I vote for option 2. I've never been a fan of pushing directly to master. I think that creating a PR is not much overhead, and if it's a small thing (like updating the version number for pip wheels or fixing a typo etc), you can just approve and merge it yourself.

[bernhardpg]

Attempting to fix this in #561. Now jobs are running for the merged commit, waiting to see if everything works as expected.

[bernhardpg]

FYI @RussTedrake this is now resolved (fixed in #561 ). I pushed a commit with some minimal changes to master to test this, and indeed tests are running as desired. Closing this issue.