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

@@ -42,11 +42,14 @@ 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
+
       - name: Lint
-        uses: golangci/golangci-lint-action@v6
-        with:
-          install-mode: goinstall
-          version: v1.64.8
+        run: golangci-lint run --allow-parallel-runners
 
   test-linux:
     name: Test (Linux)
@@ -112,4 +115,4 @@ jobs:
         run: make build-ci
 
       - name: Run smoke tests
-        run: GREYWALL_TEST_NETWORK=1 ./scripts/smoke_test.sh ./greywall
+        run: ./scripts/smoke_test.sh ./greywall