use node 24 lts (#1822)

npm@12 dropped node 25, which is an odd-numbered release and not LTS.
Required: ^22.22.2 || ^24.15.0 || >=26.0.0

.github/workflows/manifold.yml

@@ -317,7 +317,7 @@ jobs:
     - uses: actions/checkout@v6
     - uses: actions/setup-node@v6
       with:
-        node-version: 25
+        node-version: 24
         cache: 'npm'
         cache-dependency-path: bindings/**/package-lock.json
     - name: Install apt packages

.github/workflows/publish_npm.yml

@@ -25,7 +25,7 @@ jobs:
     - name: Setup Node
       uses: actions/setup-node@v6
       with:
-        node-version: 25
+        node-version: 24
         registry-url: 'https://registry.npmjs.org/'
 
     - name: Update npm # Ensure npm 11.5.1 or later for trusted publishing