Use a dedicated GitHub Actions workflow for linting TypeScript/JavaScript code

The "build" workflow builds the application for all supported targets, generates workflow artifacts from which the
builds can be downloaded by users and beta testers, and publishes nightly and production releases.

As if that wasn't enough, the workflow was also configured to perform the unrelated operation of linting the project's
TypeScript and JavaScript code.

This monolithic approach is harmful for multiple reasons:

* Makes it difficult to interpret a failed workflow run
* Unnecessarily adds a significant amount of extra content to the already extensive logs produced by the build process
* Makes the build workflow more difficult to maintain
* Increases the length of a build workflow run
* Increases the impact of a spurious failure
* Increases the turnaround time for contributors and maintainers to get feedback from the CI system

The linting operation is hereby moved to a dedicated workflow, consistent with standard practices for Arduino Tooling
projects.

.github/workflows/build.yml

@@ -395,7 +395,6 @@ jobs:
           yarn --cwd arduino-ide-extension build
           yarn test
           yarn --cwd arduino-ide-extension test:slow
-          yarn --cwd arduino-ide-extension lint
 
           yarn --cwd electron-app rebuild
           yarn --cwd electron-app build

.github/workflows/check-javascript.yml

@@ -0,0 +1,88 @@
+# Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/check-javascript-task.md
+name: Check JavaScript
+
+env:
+  # See: https://github.com/actions/setup-node/#readme
+  NODE_VERSION: 18.17
+
+# See: https://docs.github.com/actions/writing-workflows/choosing-when-your-workflow-runs/events-that-trigger-workflows
+on:
+  create:
+  push:
+    paths:
+      - '.github/workflows/check-javascript.ya?ml'
+      - '**/.eslintignore'
+      - '**/.eslintrc*'
+      - '**/.npmrc'
+      - '**/package.json'
+      - '**/package-lock.json'
+      - '**/yarn.lock'
+      - '**.jsx?'
+  pull_request:
+    paths:
+      - '.github/workflows/check-javascript.ya?ml'
+      - '**/.eslintignore'
+      - '**/.eslintrc*'
+      - '**/.npmrc'
+      - '**/package.json'
+      - '**/package-lock.json'
+      - '**/yarn.lock'
+      - '**.jsx?'
+  workflow_dispatch:
+  repository_dispatch:
+
+jobs:
+  run-determination:
+    runs-on: ubuntu-latest
+    permissions: {}
+    outputs:
+      result: ${{ steps.determination.outputs.result }}
+    steps:
+      - name: Determine if the rest of the workflow should run
+        id: determination
+        run: |
+          RELEASE_BRANCH_REGEX="refs/heads/[0-9]+.[0-9]+.x"
+          # The `create` event trigger doesn't support `branches` filters, so it's necessary to use Bash instead.
+          if [[
+            "${{ github.event_name }}" != "create" ||
+            "${{ github.ref }}" =~ $RELEASE_BRANCH_REGEX
+          ]]; then
+            # Run the other jobs.
+            RESULT="true"
+          else
+            # There is no need to run the other jobs.
+            RESULT="false"
+          fi
+
+          echo "result=$RESULT" >> $GITHUB_OUTPUT
+
+  check:
+    needs: run-determination
+    if: needs.run-determination.outputs.result == 'true'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          cache: yarn
+          node-version: ${{ env.NODE_VERSION }}
+
+      - name: Install npm package dependencies
+        env:
+          # Avoid failure of @vscode/ripgrep installation due to GitHub API rate limiting:
+          # https://github.com/microsoft/vscode-ripgrep#github-api-limit-note
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          yarn install
+
+      - name: Lint
+        run: |
+          yarn \
+            --cwd arduino-ide-extension \
+            lint

README.md

@@ -3,6 +3,7 @@
 # Arduino IDE 2.x
 
 [![Arduino IDE](https://github.com/arduino/arduino-ide/workflows/Arduino%20IDE/badge.svg)](https://github.com/arduino/arduino-ide/actions?query=workflow%3A%22Arduino+IDE%22)
+[![Check JavaScript status](https://github.com/arduino/arduino-ide/actions/workflows/check-javascript.yml/badge.svg)](https://github.com/arduino/arduino-ide/actions/workflows/check-javascript.yml)
 
 This repository contains the source code of the Arduino IDE 2.x. If you're looking for the old IDE, go to the [repository of the 1.x version](https://github.com/arduino/Arduino).