Cannot Install Softioc

Since [85c35e](https://github.com/DiamondLightSource/blueapi/commit/85c35e6a9726e2c59fb5f5bc06d51f4c482373bc) you cannot successfully run `uv pip install softioc`.

This is a necessary step of setup-scratch (I think). This makes Blueapi undeployable.

## Steps To Reproduce
Steps to reproduce the behavior:
1. Clone Blueapi
2. Run dev container
3. Run `uv sync`
4. Run `uv pip install softioc`
5. See error

## Acceptance Criteria
- Softioc can be installed

Start by checking the change at commit 85c35e and the setup-scratch path involved in the dev-container setup. Reproduce the failure with `uv sync` followed by `uv pip install softioc`, then inspect the reported installation error and relevant dependency configuration. Done means the command succeeds and the documented setup path no longer leaves Blueapi undeployable.

Written by the indexing model from the issue text.