ci(github): stop building on node <18

Author: djcsdy

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [14.x, 16.x, 18.x]
+        node-version: [18.x]
     steps:
       - name: Find yarn cache
         id: find-yarn-cache