Remove the unused 'lint' Makefile target (#2555)

The 'lint' target is no longer used throughout CI since the integration
with golangci-lint, which runs both the goimports and gofmt tooling
under-the-hood.

Signed-off-by: timflannagan <timflannagan@gmail.com>

Makefile

@@ -186,10 +186,6 @@ clean:
 	@rm -rf test/e2e/log
 	@rm -rf e2e.namespace
 
-lint:
-	find . -name '*.go' -not -path "./vendor/*" -not -path "./pkg/lib/operatorclient/operatorclientmocks/*" | xargs gofmt -w
-	find . -name '*.go' -not -path "./vendor/*" -not -path "./pkg/lib/operatorclient/operatorclientmocks/*" | xargs goimports -w
-
 # Copy CRD manifests
 manifests: vendor
 	./scripts/copy_crds.sh