Replace setup-go/setup-node actions with manual install for Gitea runner compatibility

.gitea/workflows/dev.yml

@@ -19,9 +19,9 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Setup Go
-        uses: actions/setup-go@v5
-        with:
-          go-version: "1.23"
+        run: |
+          curl -sL https://go.dev/dl/go1.23.6.linux-amd64.tar.gz | tar -C /usr/local -xz
+          echo "/usr/local/go/bin" >> $GITHUB_PATH
 
       - name: Run backend tests
         run: go test ./...
@@ -32,9 +32,9 @@ jobs:
         working-directory: ./go-backend
 
       - name: Setup Node
-        uses: actions/setup-node@v4
-        with:
-          node-version: "22"
+        run: |
+          curl -sL https://deb.nodesource.com/setup_22.x | bash -
+          apt-get install -y nodejs
 
       - name: Install frontend deps
         run: npm ci