Build/Test Tools: Use NodeJS 14 in GitHub Action workflows.

14.x is the current LTS release, and is what `trunk` currently runs.

See #50401.

git-svn-id: https://develop.svn.wordpress.org/trunk@49782 602fd350-edb4-49c9-b593-d223f7449a82

.github/workflows/coding-standards.yml

@@ -105,7 +105,7 @@ jobs:
       - name: Install NodeJS
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Cache NodeJS modules
         uses: actions/cache@v2

.github/workflows/end-to-end-tests.yml

@@ -65,7 +65,7 @@ jobs:
       - name: Install NodeJS
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Cache NodeJS modules
         uses: actions/cache@v2

.github/workflows/javascript-tests.yml

@@ -45,7 +45,7 @@ jobs:
       - name: Install NodeJS
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Cache NodeJS modules
         uses: actions/cache@v2

.github/workflows/phpunit-tests.yml

@@ -66,7 +66,7 @@ jobs:
       - name: Install NodeJS
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Cache NodeJS modules
         uses: actions/cache@v2
@@ -161,7 +161,7 @@ jobs:
       - name: Install NodeJS
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Use cached Node modules
         uses: actions/cache@v2

.github/workflows/verify-npm-on-windows.yml

@@ -47,7 +47,7 @@ jobs:
       - name: Install NodeJS
         uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 14
 
       - name: Get NPM cache directory
         id: npm-cache