[1.x] chore: resolve node deprecation warnings in workflows (#4081)

* chore: update frontend workflow

Backport of 356f97641e

* chore: bump default node version and `flarum/action-build`

* fix

* dummy commit

js-packages/tsconfig/tsconfig.json

@@ -1,5 +1,6 @@
 {
   "compilerOptions": {
+    "skipLibCheck": true,
     "allowUmdGlobalAccess": true,
     "sourceMap": true,
     "strict": true,