feat(gha): enable npm cache

The `verify.yml` workflow sets up Node.js with the npm cache enabled.
Includes other minor changes.

.github/workflows/verify.yml

@@ -7,19 +7,19 @@ on:
       - main
       - migrate-to-typescript # TODO: until the migration is complete
       - migrate-to-typescript-verify # TODO: remove after the experiment
+
   pull_request:
     branches:
       - dev
       - main
       - migrate-to-typescript # TODO: until the migration is complete
-  workflow_dispatch: # TODO: to manually run the tests. remove later
 
 jobs:
   verify:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        node-version: [18.x, 20.x, 22.x]
+        node-version: [18, 20, 22]
 
     runs-on: ${{ matrix.os }}
 
@@ -30,6 +30,7 @@ jobs:
         uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
+          cache: npm
 
       - run: npm ci