Run `arm64` `e2e` tests for every pull request rather than on nightly schedule

[jmhbnz]

What would you like to be added?

Recently in #16801 we introduced on demand github actions runners for the arm64 platform.

Having on demand runner infrastructure in place means we should now have enough capacity to begin running arm64 tests for every pull request.

We should update our .github/workflows/e2e-arm64-nightly.yaml workflow to switch from scheduled nightly runs to instead running on: [push, pull_request]: https://github.com/etcd-io/etcd/blob/main/.github/workflows/e2e-arm64-nightly.yaml#L7-L8

Why is this needed?

Gain greater confidence and samples of e2e tests running against arm64 cpu architecture.

Hopefully detect issues before pull requests are merged to main.

[mingli103]

Hi @jmhbnz please assign this issue to me.

[jmhbnz]

One further thought for this issue @mingli103. Now that we are moving to on: [push, pull_request] for the e2e arm64 workflow we can actually move away from having two separate files.

Currently we have:

• .github/workflows/e2e-arm64-template.yaml - Shared template
• .github/workflows/e2e-arm64-nightly.yaml - Runs template against both release-3.5 and main branches nightly.

Moving forward we can just rename .github/workflows/e2e-arm64-template.yaml to .github/workflows/e2e-arm64.yaml and delete the other file. We can then just make the template file a standard workflow that will run on pull request.

[jmhbnz]

Closed as completed in #16950, thanks @mingli103 🙏🏻