Add x-access-token to GH token in URL (#202)

Add the x-access-token prefix to the GH token when setting the remote
origin, since the token is generated from a JWT and not someone's PAT
it needs to have this prefix.

Github docs: https://docs.github.com/en/enterprise-cloud@latest/apps/creating-github-apps/authenticating-with-a-github-app/authenticating-as-a-github-app-installation#about-authentication-as-a-github-app-installation

Author: avangelillo

serverless/release.sh

@@ -100,7 +100,7 @@ if [ "$PROD_RELEASE" = true ] ; then
     git commit -m "Bump version from ${CURRENT_VERSION} to ${VERSION}"
     # git push origin main
     echo "pushing to remote branch"
-    git remote set-url origin https://$GH_TOKEN@github.com/DataDog/datadog-cloudformation-macro.git
+    git remote set-url origin https://x-access-token:$GH_TOKEN@github.com/DataDog/datadog-cloudformation-macro.git
     git push origin main
 
     # Create a github release