Check/fix problems with npm configuration

The "Check npm" template provides actions and a GitHub Actions workflow used to check for problems with a project's npm
configuration files.

In addition to the `package.json` file previously used, we are now using an `.npmrc` configuration file. It will be
useful to have some validation for this file. npm provides a `config fix` command which automatically fixes any problems
that are detected with the npm configuration. In addition to using it for that purpose, it can also serve as a check by
running the command via the GitHub Actions workflow, then checking for any diff.

Beyond the automated fixes, it is hoped that the parsing of the configuration that npm must perform to check for any
needed fixes provides a basic validation of the configuration. Unfortunately npm's parser is extremely lenient, so the
validation is not at all comprehensive. However, it is probably better than nothing, simple to implement, and no
alternatives were found.

Author: per1234

.github/workflows/check-npm-task.yml

@@ -125,3 +125,45 @@ jobs:
             --color \
             --exit-code \
             "${{ matrix.project.path }}/package-lock.json"
+
+  check-config:
+    name: check-config (${{ matrix.project.path }})
+    needs: run-determination
+    if: needs.run-determination.outputs.result == 'true'
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+
+    strategy:
+      fail-fast: false
+      matrix:
+        project:
+          # TODO: add paths of all npm-managed projects in the repository here.
+          - path: .
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v5
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version-file: "${{ matrix.project.path }}/package.json"
+
+      - name: Install Task
+        uses: arduino/setup-task@v2
+        with:
+          repo-token: ${{ secrets.GITHUB_TOKEN }}
+          version: 3.x
+
+      - name: Fix problems in npm configuration file
+        run: |
+          task npm:fix-config \
+            PROJECT_PATH="${{ matrix.project.path }}"
+
+      - name: Check if fixes are needed in npm configuration file
+        run: |
+          git diff \
+            --color \
+            --exit-code \
+            "${{ matrix.project.path }}/.npmrc"

.npmrc

@@ -1,3 +1,3 @@
 # See: https://docs.npmjs.com/cli/configuring-npm/npmrc
 
-engine-strict = true
+engine-strict=true

Taskfile.yml

@@ -307,6 +307,19 @@ tasks:
           markdownlint-cli \
             "**/*.md"
 
+  # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/check-npm-task/Taskfile.yml
+  npm:fix-config:
+    desc: |
+      Fix problems with the npm configuration file.
+      Environment variable parameters:
+      - PROJECT_PATH: Path of the npm-managed project (default: {{.DEFAULT_NPM_PROJECT_PATH}}).
+    dir: "{{default .DEFAULT_NPM_PROJECT_PATH .PROJECT_PATH}}"
+    cmds:
+      - |
+        npm config \
+          --location project \
+          fix
+
   # Source: https://github.com/arduino/tooling-project-assets/blob/main/workflow-templates/assets/npm-task/Taskfile.yml
   npm:install-deps:
     desc: |