CI workflows support workflow_dispatch event

[bfops]

Description of Changes

Add workflow_dispatch event support to ci.yml.

This allows us to trigger workflow runs manually (see benchmarks).

API and ABI breaking changes

No

Expected complexity level and risk

2

Testing

Describe any testing you've done, and any testing you'd like your reviewers to do,
so that you're confident that all the changes work as expected!

• We're at least still running the normal events properly https://github.com/clockworklabs/SpacetimeDB/actions/runs/9213356867/job/25347061394
• Can't test the manual workflow_dispatch step until it's merged

[kazimuth]

Makes sense to me, 👍

[kurtismullins]

Nice! Just one comment: The Pull Request CI is usually a combination of a given branch merged with master to make sure that it will behave as expected when merged into master. This appears to fetch just the branch. It might not make as much sense to use "Pull Request Number" as it would to maybe use commit or branch_name for example.

That is just a nitpick -- otherwise it looks good to me!

[bfops]

Nice! Just one comment: The Pull Request CI is usually a combination of a given branch merged with master to make sure that it will behave as expected when merged into master. This appears to fetch just the branch. It might not make as much sense to use "Pull Request Number" as it would to maybe use commit or branch_name for example.

That is just a nitpick -- otherwise it looks good to me!

That's a good point, there might be an opportunity for better UX here. I can also see an argument for keeping inputs the same between workflows, though.

I'm going to merge as-is, but I promise not to take it personally if someone else cares enough to changes it!

[bfops]

I have successfully triggered a CI workflow from the Actions page!