Update websockets requirement from <14,>=9.1 to >=9.1,<15 (#1604)

Updates the requirements on [websockets](https://github.com/python-websockets/websockets) to permit the latest version.
- [Release notes](https://github.com/python-websockets/websockets/releases)
- [Commits](python-websockets/websockets@9.1...14.1)

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

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

requirements/optional.txt

@@ -12,5 +12,5 @@ boto3<=2
 SQLAlchemy>=1.4,<3
 # Socket Mode
 # websockets 9 is not compatible with Python 3.10
-websockets>=9.1,<14
+websockets>=9.1,<15
 websocket-client>=1,<2