[CI] Add a mutiPV run for matetrack

Thanks to recent commits, we can now also trust mate(d) scores from multiPV analysis for the best move, with complete PV etc. Locally I have also tested master extensively with the help of the matetrack script in multiPV analysis, with no issues reported. So I believe we can add this to our CI.

closes https://github.com/official-stockfish/Stockfish/pull/6809

No functional change

.github/workflows/matetrack.yml

@@ -24,7 +24,7 @@ jobs:
         with:
           repository: vondele/matetrack
           path: matetrack
-          ref: 6c8405fac9028ca66a077f5c96c918fec0ef8d1d
+          ref: b2c8c9599cd7173f537b28bba88f31690a6d6f62
           persist-credentials: false
 
       - name: matetrack install deps
@@ -80,6 +80,18 @@ jobs:
             exit 1
           fi
 
+      - name: Run matetrack th1 multiPV
+        working-directory: matetrack
+        run: |
+          python matecheck.py --engine /home/runner/work/Stockfish/Stockfish/Stockfish/src/stockfish --epdFile mates2000.epd --nodes 100000 --multiPV 4 | tee matecheck1mpv.out
+          ! grep "issues were detected" matecheck1mpv.out > /dev/null
+
+      - name: Run matetrack th4 multiPV
+        working-directory: matetrack
+        run: |
+          python matecheck.py --engine /home/runner/work/Stockfish/Stockfish/Stockfish/src/stockfish --epdFile mates2000.epd --nodes 100000 --threads 4 --multiPV 4 | tee matecheck4mpv.out
+          ! grep "issues were detected" matecheck4mpv.out > /dev/null
+
       - name: Run matetrack th1 with --syzygy50MoveRule false
         working-directory: matetrack
         run: |