Bump orjson from 3.9.13 to 3.9.15

Bumps [orjson](https://github.com/ijl/orjson) from 3.9.13 to 3.9.15.
- [Release notes](https://github.com/ijl/orjson/releases)
- [Changelog](https://github.com/ijl/orjson/blob/master/CHANGELOG.md)
- [Commits](ijl/orjson@3.9.13...3.9.15)

---
updated-dependencies:
- dependency-name: orjson
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -1,4 +1,4 @@
-orjson==3.9.13
+orjson==3.9.15
 hiredis==2.3.2
 pydantic==2.6.1
 pytest==7.0.1