Support for PHP 8 (#2158)

painful 66 commits later: required PHP version bumped to 7.3, plugin updates using migrations necessary!

config/packages/doctrine.yaml

@@ -11,7 +11,6 @@ doctrine:
         default_connection: default
         connections:
             default:
-                override_url: true
                 # existing migrations will fail if the schema filter is activated
                 #schema_filter: ~^(?!(bundle_migration_|kimai2_sessions))~
                 url: '%env(DATABASE_URL)%'

config/packages/doctrine_migrations.yaml

@@ -1,4 +1,7 @@
 doctrine_migrations:
+    storage:
+        table_storage:
+            table_name: 'migration_versions'
     migrations_paths:
         # namespace is arbitrary but should be different from App\Migrations
         # as migrations classes should NOT be autoloaded