Adhere deprecation notes

- Use `when:`
- Remove `group: lint`

.woodpecker/.database_checks.yml

@@ -3,8 +3,9 @@ matrix:
     - PHP_MAJOR_VERSION: 8.2
       PHP_VERSION: 8.2.16
 
-branches:
-  exclude: [ stable ]
+when:
+  - branch:
+      exclude: [ stable ]
 
 # This forces CI executions at the "opensocial" labeled location (because of much more power...)
 labels:

.woodpecker/.messages.po_check.yml

@@ -8,5 +8,6 @@ steps:
     commands:
       - /check-messages.sh
 
-branches:
-  exclude: [ stable ]
+when:
+  - branch:
+      exclude: [ stable ]

.woodpecker/.phpunit.yml

@@ -18,7 +18,6 @@ labels:
 steps:
   php-lint:
     image: php:${PHP_MAJOR_VERSION}
-    group: lint
     commands:
       - find . -name \*.php -not -path './vendor/*' -not -path './view/asset/*' -print0 | xargs -0 -n1 php -l
   restore_cache: