chore!: migrate to Node 18

Author: feywind

.github/.OwlBot.lock.yaml

@@ -1,4 +1,4 @@
-# Copyright 2024 Google LLC
+# Copyright 2025 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,5 +13,4 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-nodejs:latest
-  digest: sha256:609822e3c09b7a1bd90b99655904609f162cc15acb4704f1edf778284c36f429
-# created: 2024-10-01T19:34:30.797530443Z
+  digest: sha256:ebf1487fdb5be0d02d49a20b01547be3cd15cbd03f4ded7b47c65eae7920a080

.github/sync-repo-settings.yaml

@@ -8,9 +8,9 @@ branchProtectionRules:
       - "ci/kokoro: Samples test"
       - "ci/kokoro: System test"
       - lint
-      - test (14)
-      - test (16)
       - test (18)
+      - test (20)
+      - test (22)
       - cla/google
       - windows
       - OwlBot Post Processor

.github/workflows/ci.yaml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node: [14, 16, 18, 20]
+        node: [18, 20, 22]
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
@@ -32,7 +32,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: 18
       - run: npm install --engine-strict
       - run: npm test
         env:
@@ -43,7 +43,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: 18
       - run: npm install
       - run: npm run lint
   docs:
@@ -52,7 +52,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
         with:
-          node-version: 14
+          node-version: 18
       - run: npm install
       - run: npm run docs
       - uses: JustinBeckwith/linkinator-action@v1