Hyperstyle

**Python**:
- Disable WPS427 (unreachable code) since it conflicts with W0101
- Add a custom tip for the bad augmented assign pattern

**Java**:
- Disable MissingSerialVersionUID inspection

- Bump version 1.2.3 -> 1.2.4
- Do not fail the tool if linters are not installed ([issue143](https://github.com/hyperskill/hyperstyle/issues/143) solved)

Hyperstyle tool is ready for the production use.