Pin npm to latest v8 release to address failing PR check

npm v9 is not compatible with Node 12, so we can't update to it yet.

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

@@ -7,16 +7,19 @@ if [ ! -z "$(git status --porcelain)" ]; then
     >&2 echo "Failed: Repo should be clean before testing!"
     exit 1
 fi
-sudo npm install --force -g npm@latest
+# Pin npm to v8 since v9 doesn't support Node 12.
+# When updating this, make sure to update the npm version in
+# `.github/workflows/update-dependencies.yml` too.
+sudo npm install --force -g npm@^8.19.3
 # Reinstall modules and then clean to remove absolute paths
 # Use 'npm ci' instead of 'npm install' as this is intended to be reproducible
 npm ci
 npm run removeNPMAbsolutePaths
 # Check that repo is still clean
 if [ ! -z "$(git status --porcelain)" ]; then
     # If we get a fail here then the PR needs attention
-    >&2 echo "Failed: node_modules are not up to date. Run 'npm ci && npm run removeNPMAbsolutePaths' on a macOS machine to update. Note it is important this command is run on macOS and not any other operating system as there is one dependency (fsevents) that is needed for macOS and may not be installed if the command is run on a Windows or Linux machine."
+    >&2 echo "Failed: node_modules are not up to date. Add the 'Update dependencies' label to your PR to update them. Note it is important that node modules are updated on macOS and not any other operating system as there is one dependency (fsevents) that is needed for macOS and may not be installed if dependencies are updated on a Windows or Linux machine."
     git status
     exit 1
 fi
-echo "Success: node_modules are up to date"
+echo "Success: node_modules are up to date"

.github/workflows/update-dependencies.yml

@@ -27,7 +27,10 @@ jobs:
       run: |
         git fetch origin "$BRANCH" --depth=1
         git checkout "origin/$BRANCH"
-        sudo npm install --force -g npm@latest
+        # Pin npm to v8 since v9 doesn't support Node 12.
+        # When updating this, make sure to update the npm version in
+        # `.github/workflows/script/check-node-modules.sh` too.
+        sudo npm install --force -g npm@^8.19.3
         npm install
         npm ci
         npm run removeNPMAbsolutePaths