This patch was taken from Arch Linux repositories:
https://gitlab.archlinux.org/archlinux/packaging/packages/opensnitch/-/blob/main/use-system-python-packages.patch
--- a/ui/Makefile
+++ b/ui/Makefile
@@ -3,16 +3,13 @@ all: opensnitch/resources_rc.py
 install:
 	@pip3 install --upgrade .
 
-opensnitch/resources_rc.py: translations deps
+opensnitch/resources_rc.py: translations
 	@pyrcc5 -o opensnitch/resources_rc.py opensnitch/res/resources.qrc
 	sed -i 's/^import ui_pb2/from . import ui_pb2/' opensnitch/ui_pb2*
 
 translations:
 	@cd i18n ; make
 	
-deps:
-	@pip3 install -r requirements.txt
-
 clean:
 	@rm -rf *.pyc
 	@rm -rf opensnitch/resources_rc.py