Bash autocomplete for `git` and `tox` in devcontainer

[callumforrester]

Following on from DiamondLightSource/python3-pip-skeleton#126 in the old pip skeleton. It would be very nice to have git extended autocompletion in the devcontainer, the tox autocompletion would also be nice.

[coretl]

Since #216 you get git autocompletion, not sure it's worth doing tox as we are likely to be using uv at some point in the medium term

[callumforrester]

Agreed, closing, thanks