Remove redundant cache: npm in CI workflow

actions/setup-node v6 automatically enables caching when
devEngines.packageManager is set to npm (which it is), so this
configuration is redundant.

Author: lberrymage

.github/workflows/build.yaml

@@ -19,6 +19,5 @@ jobs:
         with:
           node-version: 24
           check-latest: true
-          cache: npm
       - run: npm install -g @angular/cli && npm ci && ng build
       - run: ng lint