probe: plain git checkout

.gitea/workflows/probe.yml

@@ -4,10 +4,14 @@ jobs:
   windows:
     runs-on: windows-latest
     steps:
+      # Plain git, no `uses:` — no node/action cache on the host needed.
       - name: Checkout
-        uses: actions/checkout@v4
-        with:
-          fetch-depth: 0
+        shell: powershell
+        run: |
+          git init -q .
+          git fetch -q --tags "$env:GITHUB_SERVER_URL/$env:GITHUB_REPOSITORY.git" "$env:GITHUB_SHA"
+          if ($LASTEXITCODE) { exit 1 }
+          git checkout -q --force FETCH_HEAD
       - name: Setup Flutter (stable, cached on the runner host)
         shell: powershell
         run: |