Run ESLint on CI

Run the ESLint static analysis tool on any code that is submitted, to
find possible bugs such as undefined functions and variables. We may
want to adjust the ESLint settings over time, but this seems like a
good start.

This is merged into the previous check-translations.yml action, because
that's also a form of linting. Possibly that could be reimplemented as
an ESLint plugin.

.github/workflows/lint.yml

@@ -1,6 +1,6 @@
-# This workflow runs the tools/check-translations.js script to make sure that the translation data is valid.
+# Lint PRs and pushes to the main branch
 
-name: Check Translations
+name: Lint
 
 env:
   NODE_VERSION: 21.x
@@ -13,7 +13,7 @@ on:
     branches: [ "main" ]
 
 jobs:
-  test:
+  build:
     runs-on: ubuntu-latest
 
     steps:
@@ -24,5 +24,10 @@ jobs:
         node-version: ${{ env.NODE_VERSION }}
         cache: 'npm'
         cache-dependency-path: ./package-lock.json
-    - run: npm ci
-    - run: npm run check-translations
+    - name: Install dependencies
+      run: npm ci
+    - name: Run ESLint
+      run: npx eslint
+    - name: Check translations
+      if: '!cancelled()'
+      run: npm run check-translations