Update arviz requirement from >=1.0.0rc0 to >=1.2.0

Updates the requirements on [arviz](https://github.com/arviz-devs/arviz) to permit the latest version.
- [Release notes](https://github.com/arviz-devs/arviz/releases)
- [Changelog](https://github.com/arviz-devs/arviz/blob/main/CHANGELOG.md)
- [Commits](arviz-devs/arviz@v1.0.0rc0...v1.2.0)

---
updated-dependencies:
- dependency-name: arviz
  dependency-version: 1.2.0
  dependency-type: direct:development
...

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

Author: dependabot[bot]

requirements-dev.txt

@@ -1,4 +1,4 @@
-arviz>=1.0.0rc0
+arviz>=1.2.0
 build
 clickhouse-driver
 flake8