run phpmd in own woodpecker job

.woodpecker/.code_standards_check.yml

@@ -36,11 +36,7 @@ steps:
         - '.composer'
     volumes:
       - /tmp/drone-cache:/tmp/cache
-  phpmd:
-    image: php:8.3
-    commands:
-      - ./bin/composer.phar run phpmd
-  code_style:
+  check:
     image: php:8.3
     commands:
       - echo "**** Use bin/dev/fix-codestyle.sh in case of errors ****"

.woodpecker/.phpmd_check.yml

@@ -0,0 +1,22 @@
+# SPDX-FileCopyrightText: 2010 - 2024 the Friendica project
+#
+# SPDX-License-Identifier: CC0-1.0
+
+# The phpmd check is just triggered for PRs and pushes to non-stable branches of Friendica
+when:
+  branch:
+    exclude: [ stable ]
+  event: [ pull_request, push ]
+
+steps:
+  composer_install:
+    image: composer
+    commands:
+      - mkdir addon
+      - export COMPOSER_HOME=.composer
+      - ./bin/composer.phar install
+
+  phpmd:
+    image: php:8.3
+    commands:
+      - ./bin/composer.phar run phpmd