test with go1.21 patch

.github/workflows/gotest.yml

@@ -49,20 +49,21 @@ jobs:
           distribution: goreleaser
           version: "~> v1"
           args: release --clean --snapshot --skip=publish
-  test-win7-go1_20:
+  test-win7-patch:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout tsshd
+      - name: Checkout trzsz-ssh
         uses: actions/checkout@v4
       - name: Set up Go
         uses: actions/setup-go@v5
         with:
-          go-version: "1.20"
+          go-version: "1.21"
+      - name: Revert Go1.21
+        run: |
+          cd $(go env GOROOT)
+          curl https://github.com/golang/go/commit/9e43850a3298a9b8b1162ba0033d4c53f8637571.diff | patch --verbose -R -p 1
       - name: Build tsshd
         run: |
-          sed -i 's/go 1\.21/go 1.20/g' go.mod
-          go get github.com/xtaci/kcp-go/v5@v5.6.1 github.com/quic-go/quic-go@v0.40.1
-          go mod tidy
-          go test -v -tags win7 -count=1 ./tsshd
-          GOOS=windows GOARCH=386 go build -tags win7 -o tsshd_win7_i386/ ./cmd/tsshd/
-          GOOS=windows GOARCH=amd64 go build -tags win7 -o tsshd_win7_x86_64/ ./cmd/tsshd/
+          go test -v -count=1 ./tsshd
+          GOOS=windows GOARCH=386 go build -o tsshd_win7_i386/ ./cmd/tsshd/
+          GOOS=windows GOARCH=amd64 go build -o tsshd_win7_x86_64/ ./cmd/tsshd/