Bump pytz from 2021.1 to 2021.3
Bumps [pytz](https://github.com/stub42/pytz) from 2021.1 to 2021.3.
- [Release notes](https://github.com/stub42/pytz/releases)
- [Commits](https://github.com/stub42/pytz/compare/release_2021.1...release_2021.3)
---
updated-dependencies:
- dependency-name: pytz
dependency-type: direct:production
update-type: version-update:semver-minor
...
Signed-off-by: dependabot[bot] <support@github.com>
dependabot[bot]