Test builds with #[cfg(dual_funding)] enabled

Author: dunxen

ci/check-cfg-flags.py

@@ -92,6 +92,8 @@ def check_cfg_tag(cfg):
         pass
     elif cfg == "require_route_graph_test":
         pass
+    elif cfg == "dual_funding":
+        pass
     else:
         print("Bad cfg tag: " + cfg)
         assert False

ci/ci-tests.sh

@@ -176,3 +176,4 @@ fi
 echo -e "\n\nTest cfg-flag builds"
 RUSTFLAGS="--cfg=taproot" cargo test --verbose --color always -p lightning
 RUSTFLAGS="--cfg=async_signing" cargo test --verbose --color always -p lightning
+RUSTFLAGS="--cfg=dual_funding" cargo test --verbose --color always -p lightning