Build(deps): Bump bitflags from 1.2.1 to 1.3.1

Bumps [bitflags](https://github.com/bitflags/bitflags) from 1.2.1 to 1.3.1.
- [Release notes](https://github.com/bitflags/bitflags/releases)
- [Changelog](https://github.com/bitflags/bitflags/blob/main/CHANGELOG.md)
- [Commits](bitflags/bitflags@1.2.1...1.3.1)

---
updated-dependencies:
- dependency-name: bitflags
  dependency-type: indirect
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]