Fix workflow to update dependencies

Port over the fix from
https://github.com/github/codeql-action/pull/1544
and share code so these scripts don't get out of sync again.

.github/workflows/script/check-node-modules.sh

@@ -7,17 +7,9 @@ if [ ! -z "$(git status --porcelain)" ]; then
     >&2 echo "Failed: Repo should be clean before testing!"
     exit 1
 fi
-# When updating this, make sure to update the npm version in
-# `.github/workflows/update-dependencies.yml` too.
-sudo npm install --force -g npm@9.2.0
 
-# clean the npm cache to ensure we don't have any files owned by root
-sudo npm cache clean --force
+"$(dirname "$0")/update-node-modules.sh" check-only
 
-# Reinstall modules and then clean to remove absolute paths
-# Use 'npm ci' instead of 'npm install' as this is intended to be reproducible
-npm ci
-npm run removeNPMAbsolutePaths
 # Check that repo is still clean
 if [ ! -z "$(git status --porcelain)" ]; then
     # If we get a fail here then the PR needs attention

.github/workflows/script/update-node-modules.sh

@@ -0,0 +1,18 @@
+if [ "$1" != "update" && "$1" != "check-only" ]; then
+    >&2 echo "Failed: Invalid argument. Must be 'update' or 'check-only'"
+    exit 1
+fi
+
+sudo npm install --force -g npm@9.2.0
+
+# clean the npm cache to ensure we don't have any files owned by root
+sudo npm cache clean --force
+
+if [ "$1" = "update" ]; then
+    npm install
+fi
+
+# Reinstall modules and then clean to remove absolute paths
+# Use 'npm ci' instead of 'npm install' as this is intended to be reproducible
+npm ci
+npm run removeNPMAbsolutePaths