Update run-tests.yml

Author: freekmurze

.github/workflows/run-tests.yml

@@ -9,7 +9,7 @@ jobs:
             fail-fast: false
             matrix:
                 os: [ubuntu-latest]
-                php: [8.1, 8.0, 7.4, 7.3]
+                php: [8.1, 8.0, 7.4]
                 dependency-version: [prefer-lowest, prefer-stable]
 
         name: P${{ matrix.php }} - ${{ matrix.dependency-version }} - ${{ matrix.os }}