[ci] do not locally execute a script intended for ci

scripts/github-actions/check-format.sh

@@ -1,20 +1,24 @@
 #!/usr/bin/env bash
 
-set -eufo pipefail
-# We want to see what's going on
-set -x
+if [ ! -n "${GITHUB_WORKFLOW}" ]; then
+  echo "Do not run this script locally; use ./scripts/format.sh"
+else
+  set -eufo pipefail
+  # We want to see what's going on
+  set -x
 
-# The ruby version may have been set by the CI runner. Stash
-# changes while we check to see if we need to reformat the
-# code.
-git config user.email "[email protected]"
-git config user.name "CI Build"
-git commit -am 'Temp commit to allow format to run cleanly'
+  # The ruby version may have been set by the CI runner. Stash
+  # changes while we check to see if we need to reformat the
+  # code.
+  git config user.email "[email protected]"
+  git config user.name "CI Build"
+  git commit -am 'Temp commit to allow format to run cleanly'
 
-# Fail the build if the format script needs to be re-run
-./scripts/format.sh
-git diff --exit-code
+  # Fail the build if the format script needs to be re-run
+  ./scripts/format.sh
+  git diff --exit-code
 
-# Now we're made it out, reapply changes made by the build
-# runner
-git reset --soft HEAD^
+  # Now we're made it out, reapply changes made by the build
+  # runner
+  git reset --soft HEAD^
+fi