ci(windows-smoke): fetch the branch to build into a worktree

A second actions/checkout in the same job fails on the Windows host runner
(Access is denied on the cached action's pack file).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

.gitea/workflows/windows-smoke.yml

@@ -43,12 +43,16 @@ jobs:
           Invoke-WebRequest -Uri "$env:GITEA_URL/$env:REPO/releases/download/latest/LotusChat-x86_64-setup.exe" -OutFile smoke-installer\setup.exe
           Get-Item smoke-installer\setup.exe | Select-Object Name, Length
 
+      # A second actions/checkout in one job trips over the host runner's
+      # action cache on Windows ("Access is denied" on its pack files), so
+      # fetch the branch into a worktree with plain git instead.
       - name: Check out the branch to build
         if: ${{ inputs.ref != '' }}
-        uses: actions/checkout@v4
-        with:
-          ref: ${{ inputs.ref }}
-          path: build-src
+        shell: powershell
+        run: |
+          git fetch --depth=1 origin "${{ inputs.ref }}"
+          git worktree add --force build-src FETCH_HEAD
+          git -C build-src log --oneline -1
 
       - name: Build the branch
         if: ${{ inputs.ref != '' }}