fixup! TO-DROP: ci: test various patch levels of the MSYS2 runtime

Author: dscho

.github/workflows/main.yml

@@ -73,7 +73,7 @@ jobs:
     - name: replace the MSYS2 runtime
       shell: powershell
       run: |
-        $headers = @{ Authorization = "token '${{ secrets.GITHUB_TOKEN }}'" }
+        $headers = @{ Authorization = "token ${{ secrets.GITHUB_TOKEN }}" }
 
         $run_url = "https://api.github.com/repos/dscho/Cygwin-msys2-fork/actions/runs/${{ matrix.n.run }}/artifacts"
         $run = ((Invoke-WebRequest -Headers $headers $run_url).content | ConvertFrom-JSON)