chg: Reduce visibility of low-level TCP socket creation

src/net/tcp_server_socket.cpp

@@ -31,7 +31,7 @@
 
 namespace rmrf::net {
 
-auto_fd create_tcp_server_socket(const socketaddr& socket_identifier) {
+static auto_fd create_tcp_server_socket(const socketaddr& socket_identifier) {
     auto_fd socket_fd{socket(socket_identifier.family(), SOCK_STREAM, 0)};
 
     if (!socket_fd.valid()) {