As suggested in #108669, the "Navigate during Transform" option has
been removed and this feature works by default.
Now if you press `G`, `R` or `S` to move, rotate or scale an object you
can also navigate in the viewport.
Note that this update modifies the default keymap.
Now pressing `Alt` is required for the following modals:
- `PROPORTIONAL_SIZE_UP`,
- `PROPORTIONAL_SIZE_DOWN`,
- `PROPORTIONAL_SIZE`,
- `AUTOIK_CHAIN_LEN_UP`,
- `AUTOIK_CHAIN_LEN_DOWN`,
- `AUTOCONSTRAIN`,
- `AUTOCONSTRAINPLANE`.
Pull Request: https://projects.blender.org/blender/blender/pulls/109388