Finish converting all events to jspecify annotations

patches/api/Add-ElderGuardianAppearanceEvent.patch

@@ -51,6 +51,7 @@ index 0000000000000000000000000000000000000000..00000000000000000000000000000000
 +     *
 +     * @return The elder guardian
 +     */
++    @Override
 +    public ElderGuardian getEntity() {
 +        return (ElderGuardian) super.getEntity();
 +    }