chore(deps): bump actions/setup-node from 6 to 6.3.0

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 6 to 6.3.0.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](https://github.com/actions/setup-node/compare/v6...v6.3.0)

---
updated-dependencies:
- dependency-name: actions/setup-node
  dependency-version: 6.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/deltachat-rpc-server.yml

@@ -513,7 +513,7 @@ jobs:
             deltachat-rpc-server/npm-package/*.tgz
 
       # Configure Node.js for publishing.
-      - uses: actions/setup-node@v6
+      - uses: actions/setup-node@v6.3.0
         with:
           node-version: 20
           registry-url: "https://registry.npmjs.org"

.github/workflows/jsonrpc-client-npm-package.yml

@@ -22,7 +22,7 @@ jobs:
           show-progress: false
           persist-credentials: false
 
-      - uses: actions/setup-node@v6
+      - uses: actions/setup-node@v6.3.0
         with:
           node-version: 20
           registry-url: "https://registry.npmjs.org"

.github/workflows/jsonrpc.yml

@@ -21,7 +21,7 @@ jobs:
           show-progress: false
           persist-credentials: false
       - name: Use Node.js 18.x
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@v6.3.0
         with:
           node-version: 18.x
       - name: Add Rust cache

.github/workflows/upload-docs.yml

@@ -90,7 +90,7 @@ jobs:
           persist-credentials: false
           fetch-depth: 0 # Fetch history to calculate VCS version number.
       - name: Use Node.js
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@v6.3.0
         with:
           node-version: '18'
       - name: npm install