update PR validation and daily runs to reduce PR dependance on ARM64 runners

[simongdavies]

Helps to speed up PR validation whilst we have limited ARM runners, some validation/tests are moved to a daily job that runs at 5am UTC daily, failures will result in a release blocking issue

[Copilot]

Pull request overview

This PR adjusts GitHub Actions CI to reduce arm64 runner usage on pull requests by moving full aarch64 coverage (examples + fuzzing + expanded test set) to a daily scheduled workflow, while keeping PR validation faster and less dependent on limited arm64 capacity.

Changes:

• Update PR validation to skip arm64 example runs and run arm64 fuzzing only on the daily schedule.
• Add a full_aarch64 switch to the reusable build/test workflow to skip Miri + single-driver tests on aarch64 PR runs while still running them in the daily workflow.
• Introduce a new scheduled DailyArm64.yml workflow that restores full aarch64 coverage and files a release-blocking issue on failure.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
.github/workflows/ValidatePullRequest.yml	Stops running arm64 examples/fuzzing on PRs (moved to daily) to conserve arm64 runners.
.github/workflows/dep_build_test.yml	Adds full_aarch64 to control whether Miri/single-driver tests run on aarch64.
.github/workflows/DailyArm64.yml	New daily scheduled workflow to run full aarch64 coverage and open a release-blocking issue on failure.

[danbugs]

Mostly LGTM. Just one question.

[simongdavies]

yeah I'm wondering why this looks different to report-ci-status in ValidatePullRquest.yml (the if statement that is)

All the daily jobs failure notify steps are defined like this e.g. https://github.com/hyperlight-dev/hyperlight/blob/main/.github/workflows/DailyBenchmarks.yml

[ludfjig]

Ah I see didn't see that other workflow already use similar pattern