File getMimeType throws exception if no mime type can be set, fixes for phpstan checks

src/Logging/Logger/Flag.php

@@ -63,7 +63,7 @@ enum Flag: int
 	/**
 	 * Get internal name from int value
 	 *
-	 * @param  int  $value
+	 * @param  value-of<self::VALUES>  $value
 	 * @return self
 	 */
 	public static function fromValue(int $value): self