Bump Node.js used in GitHub workflows to 18

.github/workflows/checks.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2
         with:
-          node-version: 14
+          node-version-file: ".nvmrc"
       - name: Install dependencies
         run: npm ci
       - name: Build
@@ -24,7 +24,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2
         with:
-          node-version: 14
+          node-version-file: ".nvmrc"
       - name: Install dependencies
         run: npm ci
       - name: Run lint checks
@@ -35,7 +35,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2
         with:
-          node-version: 14
+          node-version-file: ".nvmrc"
       - name: Run prettier
         run: npx prettier --check '**/*.md'
   test:
@@ -44,7 +44,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2
         with:
-          node-version: 14
+          node-version-file: ".nvmrc"
       - name: Install dependencies
         run: npm ci
       - name: Run tests

.github/workflows/publish.yml

@@ -9,7 +9,7 @@ jobs:
       - uses: actions/checkout@v2
       - uses: actions/setup-node@v2
         with:
-          node-version: "14.x"
+          node-version-file: ".nvmrc"
           registry-url: "https://registry.npmjs.org"
       - run: npm ci
       - run: npm publish

.nvmrc

@@ -0,0 +1 @@
+lts/*