Fix `make generate-deploy`
It was failing with
```
$ make generate-deploy
go generate ./pkg/install
go: directory pkg/install is outside main module
make: *** [pkg/install/generated_templates.gogen.go] Error 1
```
@@ -174,7 +174,7 @@ generate-deploy: $(GOBIN)/fluxctl
--namespace flux
$(GENERATED_TEMPLATES_FILE): pkg/install/templates/*.tmpl pkg/install/generate.go
- go generate ./pkg/install
+ cd ./pkg/install && go generate .
check-generated: generate-deploy
git diff --exit-code -- deploy/
