Release 0.28.0 (#1368)

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

## Breaking Changes

- URL-encode path parameters in generated endpoints (#1349)

## Fixes

### Fix bad code generation

#1360 by @EricAtORS

This fixes:
- missing parenthesis in to_multipart
 #1338 #1318
- missing imports in the lazy eval in to_multipart:
#931 and #1051

### Fix optional bodies

If a body is not required (the default), it will now:

1. Have `Unset` as part of its type annotation.
2. Default to a value of `UNSET`
3. Not be included in the request if it is `UNSET`

Thanks @orelmaliach for the report! Fixes #1354

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

Author: knope-bot[bot]

.changeset/fix_bad_code_generation.md

@@ -13,6 +13,34 @@ Programmatic usage of this project (e.g., importing it as a Python module) and t
 
 The 0.x prefix used in versions for this project is to indicate that breaking changes are expected frequently (several times a year). Breaking changes will increment the minor number, all other changes will increment the patch number. You can track the progress toward 1.0 [here](https://github.com/openapi-generators/openapi-python-client/projects/2).
 
+## 0.28.0 (2025-12-03)
+
+### Breaking Changes
+
+- URL-encode path parameters in generated endpoints (#1349)
+
+### Fixes
+
+#### Fix bad code generation
+
+##1360 by @EricAtORS
+
+This fixes:
+- missing parenthesis in to_multipart
+ #1338 #1318
+- missing imports in the lazy eval in to_multipart:
+##931 and #1051
+
+#### Fix optional bodies
+
+If a body is not required (the default), it will now:
+
+1. Have `Unset` as part of its type annotation.
+2. Default to a value of `UNSET`
+3. Not be included in the request if it is `UNSET`
+
+Thanks @orelmaliach for the report! Fixes #1354
+
 ## 0.27.1 (2025-11-03)
 
 ### Fixes

.changeset/fix_optional_bodies.md

@@ -17,7 +17,7 @@ dependencies = [
     "ruff>=0.2",
 ]
 name = "openapi-python-client"
-version = "0.27.1"
+version = "0.28.0"
 description = "Generate modern Python clients from OpenAPI"
 keywords = [
     "OpenAPI",