e2e: Use the GitHub token for auth

Add support for running the end-to-end test workflow for private GitHub repositories.

Signed-off-by: Stefan Prodan <stefan.prodan@gmail.com>

.github/workflows/e2e.yaml

@@ -25,6 +25,8 @@ jobs:
           flux create source git flux-system \
           --url=${{ github.event.repository.html_url }} \
           --branch=${GITHUB_REF#refs/heads/} \
+          --username=${GITHUB_ACTOR} \
+          --password=${{ secrets.GITHUB_TOKEN }} \
           --ignore-paths="clusters/**/flux-system/"
           flux create kustomization flux-system \
           --source=flux-system \