Change invalid token test to expired

It does not currently seem possible to properly configure
WireMock stubs for the completely bogus auth token to
avoid "unstubbed" request error log messages in runtime.

So, for now let's use an expired token to validate the
handling of "unauthenticated" requests.

servers/quarkus-server/src/test/java/org/projectnessie/server/TestOpenIdAuthentication.java

@@ -40,6 +40,13 @@ private String getJwtToken() {
     return Jwt.preferredUserName("test_user").issuer("https://server.example.com").sign();
   }
 
+  private String getExpiredJwtToken() {
+    return Jwt.preferredUserName("expired")
+        .issuer("https://server.example.com")
+        .expiresAt(0)
+        .sign();
+  }
+
   @Test
   void testValidJwt() {
     withClientCustomizer(
@@ -48,9 +55,9 @@ void testValidJwt() {
   }
 
   @Test
-  void testInvalidToken() {
+  void testExpiredToken() {
     withClientCustomizer(
-        b -> b.withAuthentication(BearerAuthenticationProvider.create("invalid_token")));
+        b -> b.withAuthentication(BearerAuthenticationProvider.create(getExpiredJwtToken())));
     assertThatThrownBy(() -> client().getTreeApi().getAllReferences())
         .isInstanceOfSatisfying(
             NessieNotAuthorizedException.class,