build(deps): bump actions/setup-node from 4 to 7

Bumps [actions/setup-node](https://github.com/actions/setup-node) from 4 to 7.
- [Release notes](https://github.com/actions/setup-node/releases)
- [Commits](actions/setup-node@v4...v7)

---
updated-dependencies:
- dependency-name: actions/setup-node
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/extensions.yml

@@ -24,7 +24,7 @@ jobs:
       - uses: pnpm/action-setup@v4
         with:
           package_json_file: home/.pi/agent/extensions/package.json
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@v7
         with:
           node-version: 26.0.0
           cache: pnpm