Temporarily work around gcc-13 warning bug in interfaces_tests

This can be reverted once gcc excludes lambdas with decltype(auto)
return type from its -Wdangling-reference analysis.

Author: MarcoFalke

src/test/interfaces_tests.cpp

@@ -98,7 +98,7 @@ BOOST_AUTO_TEST_CASE(findAncestorByHash)
 BOOST_AUTO_TEST_CASE(findCommonAncestor)
 {
     auto& chain = m_node.chain;
-    const CChain& active = WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return Assert(m_node.chainman)->ActiveChain());
+    const CChain& active{*WITH_LOCK(Assert(m_node.chainman)->GetMutex(), return &Assert(m_node.chainman)->ActiveChain())};
     auto* orig_tip = active.Tip();
     for (int i = 0; i < 10; ++i) {
         BlockValidationState state;