CI: Specify token when checking out demo (#401)

The existing WebAssembly CI works on personal repository, but it failed
here. This is very strange but we still have to solve it.

Combining some discussion in github-push-action's issue and my own
thought, when checking out demo, the persist-credentials is set to
false, thus the token used for further action should be specified.

See issue: #400

.github/workflows/deploy-wasm.yml

@@ -55,6 +55,7 @@ jobs:
         uses: actions/checkout@v4
         with:
           persist-credentials: false # otherwise, the token used is the GITHUB_TOKEN, instead of your personal access token.
+          token: ${{ secrets.RV32EMU_DEMO_TOKEN }}
           repository: sysprog21/rv32emu-demo
       - name: Create local changes
         if: ${{ steps.changed-files.outputs.any_changed == 'true' ||