chore(ci): add dependency audit (#7)

Author: alpha912

.github/workflows/validate-schemas.yml

@@ -19,5 +19,7 @@ jobs:
           cache: 'npm'
       - name: Install dependencies
         run: npm ci
+      - name: Audit dependencies
+        run: npm audit --omit=dev
       - name: Run schema validation
         run: npm test