Issue #3452860: Fix PHP warnings in tests

.gitlab-ci.yml

@@ -49,8 +49,8 @@ include:
 # Docs at https://git.drupalcode.org/project/gitlab_templates/-/blob/1.0.x/includes/include.drupalci.variables.yml
 ################
 variables:
-  _PHPUNIT_CONCURRENT: '0'
-  _PHPUNIT_EXTRA: '-c $CI_PROJECT_DIR/$_WEB_ROOT/core --testdox --colors=always'
+  _PHPUNIT_CONCURRENT: '1'
+#  _PHPUNIT_EXTRA: '-c $CI_PROJECT_DIR/$_WEB_ROOT/core --testdox --colors=always'
   OPT_IN_TEST_PREVIOUS_MINOR: '0'
   OPT_IN_TEST_NEXT_MINOR: '1'
   OPT_IN_TEST_NEXT_MAJOR: '1'

src/Plugin/FileMetadata/GetImageSize.php

@@ -42,7 +42,7 @@ class GetImageSize extends FileMetadataPluginBase {
    */
   protected function validateKey(mixed $key, string $method): bool {
     if (!in_array($key, $this->getSupportedKeys(), TRUE)) {
-      throw new FileMetadataException("Invalid metadata key '{$key}' specified", $this->getPluginId(), $method);
+      throw new FileMetadataException(sprintf("Invalid metadata key '%s' specified", var_export($key, TRUE)), $this->getPluginId(), $method);
     }
     return TRUE;
   }