Merge bitcoin/bitcoin#27957: net: remove unused CConnmanTest

9f0d129 net: remove unused `CConnmanTest` (brunoerg)

Pull request description:

  `CConnmanTest` was removed in fa72fce.

ACKs for top commit:
  theStack:
    ACK 9f0d129

Tree-SHA512: 9ad974e8db700e6914a3ed5c936bfe0077cb7dcac915f4efccfe14ecf1917a0eafb37ad5ce6903ed81194bd99359ab300dababa3407f6f7b4d888d459782ad58

Author: fanquake

src/net.h

@@ -1219,7 +1219,6 @@ class CConnman
         std::vector<CNode*> m_nodes_copy;
     };
 
-    friend struct CConnmanTest;
     friend struct ConnmanTestMsg;
 };