test: update DocMDP level 1 exception test to only check exception type

Removes translated message assertion for robustness.

Signed-off-by: Vitor Mattos <[email protected]>

Author: vitormattos

tests/php/Unit/Service/SignFileServiceTest.php

@@ -1176,7 +1176,6 @@ public static function providerGetNodeByIdUsingUid(): array {
 
 	public function testSignThrowsExceptionWhenDocMdpLevel1Detected(): void {
 		$this->expectException(LibresignException::class);
-		$this->expectExceptionMessage('This document is certified with DocMDP level 1 (no changes allowed) and cannot receive additional signatures');
 
 		// Create a real DocMdpHandler for this test
 		$realDocMdpHandler = new DocMdpHandler($this->l10n);