Fix violations of a handful of Error Prone checks (#5519)

Co-authored-by: Daniel Beck <1831569+daniel-beck@users.noreply.github.com>

core/src/main/java/hudson/PluginWrapper.java

@@ -721,7 +721,6 @@ public class PluginWrapper implements Comparable<PluginWrapper>, ModelObject {
 
     /**
      * Disable a plugin wihout checking any dependency. Only add the disable file.
-     * @throws IOException
      */
     private void disableWithoutCheck() throws IOException {
         try (OutputStream os = Files.newOutputStream(disableFile.toPath())) {