Fix TimestampClientHttpTest for Bouncy Castle 1.85

Update expected error message to match Bouncy Castle 1.85's hardened
ASN.1 parsing.

TAG=agy
CONV=34327f37-2d6d-4892-b442-ac8e71a7f8eb

Signed-off-by: Appu <appu@google.com>

Author: loosebazooka

sigstore-java/src/test/java/dev/sigstore/timestamp/client/TimestampClientHttpTest.java

@@ -189,7 +189,7 @@ public void timestamp_failure_responseBodyReadError() throws Exception {
                 client.timestamp(tsReq);
               });
       assertEquals(
-          "Timestamp response validation or parsing failed: unknown tag 0 encountered",
+          "Timestamp response validation or parsing failed: corrupted stream - out of bounds length found: 105 > 101",
           tse.getMessage());
     }
   }