chore(ci): update golangci-lint and fix script paths

- bump golangci-lint-action to v7 and version to v2.1.6
- correct directory paths in `smoke_test.sh`
- update `test` and `test-ci` targets in Makefile

.gitea/workflows/main.yml

@@ -42,9 +42,6 @@ jobs:
       - name: Download dependencies
         run: go mod download
 
-      - name: Download tun2socks binaries
-        run: make download-tun2socks
-
       - name: Install golangci-lint
         run: GOTOOLCHAIN=local go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.1.6