Update to upload artifact@v4

[mi-hol]

"build-libopenblt-linux" job uploads to a different path than expected by "build-firmware" jobs therefore they all fail. upload uses: path: ./deliver/libopenblt.so download uses: path: ./firmware/ext/openblt/Host/

fail to understand how this worked with v3 😦

[mck1117]

the upload vs. download describes what path to look for that file on the upload side, then where to place it on the download.

   - name: Download LibOpenBLT Tool (Linux)
      uses: actions/download-artifact@v4
      with:
        name: libopenblt-linux
        path: ./firmware/ext/openblt/Host/

means to download libopenblt-linux to ./firmware/ext/openblt/Host/

[mck1117]

done in master