Bump got and saucelabs in /fixtures/browser

Bumps [got](https://github.com/sindresorhus/got) to 11.8.6 and updates ancestor dependency [saucelabs](https://github.com/saucelabs/node-saucelabs). These dependencies need to be updated together.


Updates `got` from 8.3.2 to 11.8.6
- [Release notes](https://github.com/sindresorhus/got/releases)
- [Commits](sindresorhus/got@v8.3.2...v11.8.6)

Updates `saucelabs` from 7.2.2 to 7.3.0
- [Release notes](https://github.com/saucelabs/node-saucelabs/releases)
- [Commits](saucelabs/node-saucelabs@7.2.2...7.3.0)

---
updated-dependencies:
- dependency-name: got
  dependency-type: indirect
- dependency-name: saucelabs
  dependency-type: direct:production
...

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