update actions/checkout in GitHub Actions to v3

[striezel]

Updates the actions/checkout actions used in the GitHub Actions workflow to its newest version.

Changes in actions/checkout can be seen here: https://github.com/actions/checkout/blob/main/CHANGELOG.md

As far as I can tell this should be backwards compatible, so I do not expect any breakage.

[striezel]

It looks like the cross-compilation tests that are failing here only triggered on pull requests but not by normal commits on the master branch. So I guess they may have been broken even before this PR and it just was not noticed before this PR, because those tests do not run on normal commits.

@jk-jeon
Is this a known issue? #11 looks like it could be.

[jk-jeon]

Thanks a lot for the PR. I'm trying to looking at it. The compilation issue is an easy one, but the test failure is something I need to investigate.

It's weird. It seems all tests up to verify_compressed_cache runs successfully. verify_compressed_cache itself also seems to run without any issue I believe, as there is nothing done after printing the message "Verification succeeded. No error detected.". The next test I believe is supposed to be verify_magic_division, but the very first thing it does is to print a message, but there is nothing shown in the log...

[jk-jeon]

I'm pretty sure the problem is not in this PR so let's accept it first anyway. Thanks again!

[jk-jeon]

Okay. It turned out to be because of a wrong build target name that does not exist anymore. It was not a bug in the source. Thanks!

[striezel]

Thank you for taking the time to investigate and clearing that up. :)