Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 3 to 4.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v3...v4)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

…rkflow

The "Compile Examples" GitHub Actions workflow is configured to compile the example sketches for each of the supported
boards. This is done by using a job matrix in the GitHub Actions workflow to generate a parallel job for each board.

A GitHub Actions workflow artifact is used to transfer the sketches report files generated by the
"arduino/compile-sketches" action between this workflow's job and the "Report Size Deltas" workflow that uses the
"arduino/report-size-deltas" action to publish the data. The "actions/upload-artifact" action is used to upload the
sketches report files to the workflow artifact.

Previously, the sketches reports from all the boards were uploaded to a single artifact. However, support for uploading
multiple times to a single artifact was dropped in version 4.0.0 of the "actions/upload-artifact" action. So it is now
necessary for each of the jobs to use a separate artifact. The "arduino/report-size-deltas" action is configured to
recognize these multiple artifacts by a regular expression that matches against a standardized prefix on the artifact
names.