CI: Upgrade GitHub upload-artifact action to v4 (#1852)

CI: Upgrade GitHub upload-artifact action to v4 (#1852)

    The following artifacts were uploaded using a version of
    actions/upload-artifact that is scheduled for deprecation:
    "build-logs-macos-14-Object", "build-logs-ubuntu-22.04-Object",
    "test-logs".

This change finishes GitHub actions upgrade started in recent commit
8805c474 and removes all remaining GitHub Actions upgrade warnings.

Upgrading to actions/upload-artifact@v4 is not trivial because the new
action version uses "immutable (unless deleted)" artifacts: One GitHub
Actions job cannot add artifacts to a container created by another job.
We now add build layer dimension to the container name created inside
"build-tests" matrix, so that all layer logs are uploaded, with one
artifact container per matrix job.

Also fixed the compiler component in build-tests artifact names: Recent
commit 5a7811af intended to add "compiler dimension to avoid name
clashes" but only added a constant "-Object" suffix, resulting in log
name clashes on Ubuntu runners that test using two compilers.