Using GitHub default token in test workflow

Author: lelegard

.github/workflows/install-libsrt.yml

@@ -5,9 +5,7 @@ jobs:
   installation:
     runs-on: windows-latest
     env:
-      # The repo secret "GUEST_TOKEN" is a GitHub token without any privilege, just avoiding
-      # rate limits when using the GitHub API when downloading some prerequisites from GitHub.
-      GITHUB_TOKEN: ${{ secrets.GUEST_TOKEN }}
+      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
     - uses: actions/checkout@master
     - run: ./install-libsrt.ps1 -GitHubActions -NoPause