Bump fastavro from 1.9.4 to 1.9.7

Bumps [fastavro](https://github.com/fastavro/fastavro) from 1.9.4 to 1.9.7.
- [Release notes](https://github.com/fastavro/fastavro/releases)
- [Changelog](https://github.com/fastavro/fastavro/blob/master/ChangeLog)
- [Commits](fastavro/fastavro@1.9.4...1.9.7)

---
updated-dependencies:
- dependency-name: fastavro
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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