[CI] Fix typo in regex for filtering out failures in benchmark CI (#18905)

Author: ianayl

devops/actions/run-tests/benchmark/action.yml

@@ -162,7 +162,7 @@ runs:
         --name "$SAVE_NAME" \
         --compare-file "./llvm-ci-perf-results/results/${SAVE_NAME}_${SAVE_TIMESTAMP}.json" \
         --results-dir "./llvm-ci-perf-results/results/" \
-        --regression-filter '^[a-z_]_sycl '
+        --regression-filter '^[a-z_]+_sycl '
       echo "-----"
 
   - name: Cache changes to benchmark folder for archival purposes