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

## Breaking Changes

- Raise minimum httpx version to 0.23

### Removed ability to set an array as a multipart body

Previously, when defining a request's body as `multipart/form-data`, the
generator would attempt to generate code
for both `object` schemas and `array` schemas. However, most arrays
could not generate valid multipart bodies, as
there would be no field names (required to set the `Content-Disposition`
headers).

The code to generate any body for `multipart/form-data` where the schema
is `array` has been removed, and any such
bodies will be skipped. This is not _expected_ to be a breaking change
in practice, since the code generated would
probably never work.

If you have a use-case for `multipart/form-data` with an `array` schema,
please [open a new
discussion](https://github.com/openapi-generators/openapi-python-client/discussions)
with an example schema and the desired functional Python code.

### Change default multipart array serialization

Previously, any arrays of values in a `multipart/form-data` body would
be serialized as an `application/json` part.
This matches the default behavior specified by OpenAPI and supports
arrays of files (`binary` format strings).
However, because this generator doesn't yet support specifying
`encoding` per property, this may result in
now-incorrect code when the encoding _was_ explicitly set to
`application/json` for arrays of scalar values.

PR #938 fixes #692. Thanks @micha91 for the fix, @ratgen and
@FabianSchurig for testing, and @davidlizeng for the original report...
many years ago 😅.

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