fix(ci): use phpbench dump-file output for v1.6 compatibility

Signed-off-by: Vitor Mattos <1079143+vitormattos@users.noreply.github.com>

Author: vitormattos

.github/copilot-instructions.md

@@ -27,7 +27,7 @@ vendor-bin/phpbench/vendor/phpbench/phpbench/bin/phpbench run --bootstrap=vendor
 PHPBench automatically:
 - Runs warmup iterations (eliminates JIT/opcache startup noise)
 - Executes multiple revisions for statistical confidence
-- Reports mean, min, max, stdev, variance per benchmark
+- Reports mean, min, max, stdev, variance per benchmark (CI dump file: `build/benchmark-results.xml`)
 
 ## Compliance and contribution
 

.github/workflows/performance.yml

@@ -34,13 +34,13 @@ jobs:
           
           echo "✓ Benchmarks completed"
           echo ""
-          echo "Results saved to build/benchmark-results.json"
+          echo "Results saved to build/benchmark-results.xml"
           echo "Review: Ensure no individual benchmark takes >10ms average"
       
       - name: Save benchmark results as artifact
         if: always()
         uses: actions/upload-artifact@v4
         with:
           name: benchmark-results
-          path: build/benchmark-results.json
+          path: build/benchmark-results.xml
           retention-days: 90

composer.json

@@ -76,7 +76,7 @@
     "test:coverage": "XDEBUG_MODE=coverage vendor-bin/phpunit/vendor/phpunit/phpunit/phpunit --coverage-text --coverage-clover=build/coverage/clover.xml",
     "mutation:test": "vendor-bin/mutation/vendor/infection/infection/bin/infection --threads=max",
     "benchmark:run": "vendor-bin/phpbench/vendor/phpbench/phpbench/bin/phpbench run --bootstrap=vendor/autoload.php --report=aggregate benchmarks",
-    "benchmark:run:ci": "mkdir -p build && vendor-bin/phpbench/vendor/phpbench/phpbench/bin/phpbench run --bootstrap=vendor/autoload.php --iterations=20 --revs=10 --warmup=2 --report=aggregate --output=json:build/benchmark-results.json benchmarks",
+    "benchmark:run:ci": "mkdir -p build && vendor-bin/phpbench/vendor/phpbench/phpbench/bin/phpbench run --bootstrap=vendor/autoload.php --iterations=20 --revs=10 --warmup=2 --report=aggregate --dump-file=build/benchmark-results.xml benchmarks",
     "bin": [
       "composer bin all list"
     ]