GeezerVison

> [!IMPORTANT]
> Merging this pull request will create this release

## ❗️Breaking ❗

### Switch from `httpx` to `httpx2` in generated clients

[`httpx2`](https://pydantic.dev/docs/httpx2/get-started/) is largely
compatible with `httpx` and should only be a breaking change for users
who customize the internal `Client`.

Thanks to @s-sajid-ali and @johnthagen for making this one happen in PR
openapi-generators#1461 and discussion openapi-generators#1455!

## 🚀 Features

- Update `uv_build` to 0.13 when using `--meta=uv` (openapi-generators#1507)

## 🐛 Fixes

- Let httpx2 choose the multipart/form-data boundary (openapi-generators#1511)

### Let httpx2 choose the boundary for `multipart/form-data` requests

Since 0.29.0, generated endpoints sent every `multipart/form-data` body
with the fixed boundary `+++`, so an uploaded file containing
`\r\n--+++` was cut short at that point (openapi-generators#1509). These bodies no longer
set `Content-Type`, so httpx2 sets it with a random boundary for each
request, as single-body endpoints did before 0.29.0. Endpoints with
several body types still get a boundary (openapi-generators#947).

Co-authored-by: knope-bot[bot] <152252888+knope-bot[bot]@users.noreply.github.com>