fix(ci): run on Node 24 (openclaw 2026.9.x requires Node >=24.16 <25 || >=26.1) (#8)

Unblocks Dependabot PR #3 (openclaw 2026.7.1-2 -> 2026.9.5) which failed
build-test on Node 20, and the transitive security alerts it carries
(hono, fast-uri, ip-address, undici).

Co-authored-by: TheStreamCode <michael@mikesoft.it>

Author: TheStreamCode

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
 
       - uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020 # v7.0.0
         with:
-          node-version: 20
+          node-version: 24
           cache: npm
 
       - name: Install dependencies