chore(rpc/docs): fix cache node/npm in gh workflow

Author: snormore

.github/workflows/openrpc-docs.yml

@@ -22,12 +22,6 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Setup node.js
-        uses: actions/setup-node@v4
-        with:
-          node-version: 16
-          cache: 'npm'
-
       - name: Rust cache
         uses: swatinem/rust-cache@v2
 
@@ -90,6 +84,13 @@ jobs:
               ],
           }" > gatsby-config.js
 
+      - name: Setup node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 16
+          cache: 'npm'
+          cache-dependency-path: ./docs/rpc/docs/gatsby/package-lock.json
+
       - name: Install dependencies
         working-directory: ./docs/rpc/docs/gatsby
         run: |