ci: Update nodejs to a maintained version (#7784)

.github/workflows/appspot.yaml

@@ -23,7 +23,7 @@ jobs:
 
       - uses: actions/setup-node@v4
         with:
-          node-version: 16
+          node-version: 22
           registry-url: 'https://registry.npmjs.org'
 
       - uses: ./.github/workflows/custom-actions/prep-for-appspot

.github/workflows/nightly-demo.yaml

@@ -22,7 +22,7 @@ jobs:
 
       - uses: actions/setup-node@v4
         with:
-          node-version: 16
+          node-version: 22
           registry-url: 'https://registry.npmjs.org'
 
       # The nightly demo has its own receiver app ID that points to the nightly

.github/workflows/release-please.yaml

@@ -67,7 +67,7 @@ jobs:
 
       - uses: actions/setup-node@v4
         with:
-          node-version: 16
+          node-version: 22
           registry-url: 'https://registry.npmjs.org'
 
       - name: Compute NPM tags
@@ -140,7 +140,7 @@ jobs:
 
       - uses: actions/setup-node@v4
         with:
-          node-version: 16
+          node-version: 22
           registry-url: 'https://registry.npmjs.org'
 
       - name: Compute appspot subdomain and promotion

.github/workflows/selenium-lab-tests.yaml

@@ -250,7 +250,7 @@ jobs:
 
       - uses: actions/setup-node@v4
         with:
-          node-version: 16
+          node-version: 22
           registry-url: 'https://registry.npmjs.org'
 
       # The Docker image for this self-hosted runner doesn't contain java.

package.json

@@ -108,7 +108,7 @@
     "eme-encryption-scheme-polyfill": "^2.1.6"
   },
   "engines": {
-    "node": ">=14"
+    "node": ">=18"
   },
   "clean-package": {
     "remove": [