add test that action updates don't break other workflows (especially relock)

[h-vetinari]

The relock action has been deep red for days, meaning none of the changes to the pinning in that time have actually made it to the bots. This is obviously problematic.

In conda-forge/conda-forge-pinning-feedstock#8029, @tkelman mentioned

Not 100% sure but it looks like the relock failures are due to an incompatibility between actions/checkout@v6 and peter-evans/create-pull-request prior to 7.0.9, tagging and propagating this conda-incubator/relock-conda#441 (comment) might resolve it

CC @beckermr

[beckermr]

Ack I thought things were pinned at working versions everywhere. I'll fix this later.

Idk how a non-working update got pushed.

Even a change to the pinning the relocking script won't get propagated until a version of the action is released.

Anyone understand how things might have come undone?

[beckermr]

Ah I think this is an update to checkout v6 here combined with the current action version. The update prs do not run the relocking job and we would not see an issue until that job got run.

[beckermr]

OK things are relocking at #5156.

[h-vetinari]

Thanks a lot for the quick fix! 🙏

Ah I think this is an update to checkout v6 here combined with the current action version. The update prs do not run the relocking job and we would not see an issue until that job got run.

Sounds like we should add a test for this, so that future checkout bumps etc. don't cause issues again? This sounds like it'd be the right issue for it, so I'm reopening

[beckermr]

Yep sorry for closing early. Idk exactly how to write the test.

[h-vetinari]

How about simply running relock (without the tests) as part of regular CI?

[beckermr]

It failed at the part it makes a pr I think? The action won't do that if nothing is updated. Also I don't want to make a bunch of extra prs. Hrmmm.