Update checkout action in weekly.yml

[praveksharma]

This updates the checkout action in used in .github/workflows/weekly.yml from v2 to v4.

Weekly tests fail currently due to an unexpected formatting error which persists on re-running the failed jobs (see https://github.com/open-quantum-safe/liboqs/actions/runs/10542663074). The variable expansion for matrix.CMAKE_ARGS occurring on line 76 of weekly.yml seems to strip surrounding whitespace:

run: mkdir build && cd build && cmake -GNinja ${{ matrix.CMAKE_ARGS }} .. && cmake -LA -N ..

The tests run correctly with checkout v4 (see https://github.com/open-quantum-safe/liboqs/actions/runs/10582643980).

Fixes #1906.

[No] Does this PR change the input/output behaviour of a cryptographic algorithm (i.e., does it change known answer test values)? (If so, a version bump will be required from x.y.z to x.(y+1).0.)
[No] Does this PR change the list of algorithms available -- either adding, removing, or renaming? Does this PR otherwise change an API? (If so, PRs in fully supported downstream projects dependent on these, i.e., oqs-provider will also need to be ready for review and merge by the time this is merged.)

[SWilson4]

Man, we just can't catch a break with CI lately... thanks for debugging this @praveksharma!

Note to self: look into automatically triggering the weekly CI runs on PRs that edit their config files.

[praveksharma]

Note to self: look into automatically triggering the weekly CI runs on PRs that edit their config files.

I looked into this, here's some relevant documentation for creating path filters: https://docs.github.com/en/actions/writing-workflows/workflow-syntax-for-github-actions#onpushpull_requestpull_request_targetpathspaths-ignore

[baentsch]

Man, we just can't catch a break with CI lately... thanks for debugging this @praveksharma!

Note to self: look into automatically triggering the weekly CI runs on PRs that edit their config files.

Good proposal @SWilson4 . Possible improvement: Move this "Note to self" into an issue such as to a) not forget it and b) give others a chance to contribute.

Next point regarding not repeating a mistake: Is this workflow file also covered by #1880?