chore: Remove Travis references in scripts/check_secrets.sh (#15531)

Author: ncooke3

scripts/check_secrets.sh

@@ -22,13 +22,6 @@ echo "GITHUB_HEAD_REF: ${GITHUB_HEAD_REF:-}"
 
 check_secrets()
 {
-  # Travis: Secrets are available if we're not running on a fork.
-  if [[ -n "${TRAVIS_PULL_REQUEST:-}" ]]; then
-    if [[ "$TRAVIS_PULL_REQUEST" == "false" ||
-        "$TRAVIS_PULL_REQUEST_SLUG" == "$TRAVIS_REPO_SLUG" ]]; then
-          return 0
-    fi
-  fi
   # GitHub Actions: Secrets are available if we're not running on a fork.
   # See https://help.github.com/en/actions/automating-your-workflow-with-github-actions/using-environment-variables
   # TODO- Both GITHUB_BASE_REF and GITHUB_HEAD_REF are set in main repo