fix: include apt extra in tests

Makefile

@@ -1,4 +1,5 @@
 PROJECT=charmcraft
+SETUP_TESTS_EXTRA_ARGS=--extra apt
 
 include common.mk
 
@@ -35,11 +36,3 @@ else ifneq ($(shell which brew),)
 	sudo cp -R /usr/local/opt/[email protected] /usr/local
 	brew install multipass
 endif
-
-.PHONY: setup-tests
-setup-tests: install-uv install-build-deps ##- Set up a testing environment without linters
-ifneq ($(shell which brew),)
-	export LDFLAGS="-L/usr/local/opt/[email protected]/lib"
-	export CPPFLAGS="-I/usr/local/opt/[email protected]/include"
-endif
-	uv sync --frozen

common.mk

@@ -46,7 +46,7 @@ setup: install-uv setup-precommit ## Set up a development environment
 
 .PHONY: setup-tests
 setup-tests: install-uv install-build-deps ##- Set up a testing environment without linters
-	uv sync --frozen
+	uv sync --frozen $(SETUP_TESTS_EXTRA_ARGS)
 
 .PHONY: setup-lint
 setup-lint: install-uv install-shellcheck  ##- Set up a linting-only environment