Merge #244: ci: suppress two tidy lint issues

16dfc36 ci: avoid bugprone-unused-return-value lint in test (Sjors Provoost)
dacd5ed ci: suppress nontrivial-threadlocal lint in proxy.cpp (Sjors Provoost)

Pull request description:

  Needed for clang-22 tidy job, see:
  bitcoin/bitcoin#34662

ACKs for top commit:
  ryanofsky:
    Code review ACK 16dfc36, just switching to NOLINT to (void) since last

Tree-SHA512: fca97015733b88422f895e7a193fe6700f45a1a12904fe5f8857367561d4e2393dc0598373f908b507e8149eb4e9633f797856ff841ea80fb3e924fe786dc70b

Author: ryanofsky

src/mp/proxy.cpp

@@ -38,7 +38,7 @@
 
 namespace mp {
 
-thread_local ThreadContext g_thread_context;
+thread_local ThreadContext g_thread_context; // NOLINT(bitcoin-nontrivial-threadlocal)
 
 void LoggingErrorHandler::taskFailed(kj::Exception&& exception)
 {

test/mp/test/test.cpp

@@ -97,7 +97,7 @@ class TestSetup
                   client_connection->m_rpc_system->bootstrap(ServerVatId().vat_id).castAs<messages::FooInterface>(),
                   client_connection.get(), /* destroy_connection= */ client_owns_connection);
               if (client_owns_connection) {
-                  client_connection.release();
+                  (void)client_connection.release();
               } else {
                   client_disconnect = [&] { loop.sync([&] { client_connection.reset(); }); };
               }