fix: allow gbp dch to work in all branches

Signed-off-by: ZHANG Yuntian <yt@radxa.com>

Makefile

@@ -67,7 +67,7 @@ clean-deb:
 #
 .PHONY: dch
 dch: debian/changelog
-	EDITOR=true gbp dch --commit --debian-branch=main --release --dch-opt=--upstream
+	EDITOR=true gbp dch --ignore-branch --multimaint-merge --commit --release --dch-opt=--upstream
 
 .PHONY: deb
 deb: debian