Bump node-fetch and isomorphic-fetch

Bumps [node-fetch](https://github.com/node-fetch/node-fetch) to 2.6.9 and updates ancestor dependency [isomorphic-fetch](https://github.com/matthew-andrews/isomorphic-fetch). These dependencies need to be updated together.


Updates `node-fetch` from 1.7.3 to 2.6.9
- [Release notes](https://github.com/node-fetch/node-fetch/releases)
- [Commits](node-fetch/node-fetch@1.7.3...v2.6.9)

Updates `isomorphic-fetch` from 2.2.1 to 3.0.0
- [Release notes](https://github.com/matthew-andrews/isomorphic-fetch/releases)
- [Commits](matthew-andrews/isomorphic-fetch@v2.2.1...v3.0.0)

---
updated-dependencies:
- dependency-name: node-fetch
  dependency-type: indirect
- dependency-name: isomorphic-fetch
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>