Update paho-mqtt requirement from <2,>=1.6 to >=2.1.0,<3

Updates the requirements on [paho-mqtt](https://github.com/eclipse/paho.mqtt.python) to permit the latest version.
- [Release notes](https://github.com/eclipse/paho.mqtt.python/releases)
- [Changelog](https://github.com/eclipse/paho.mqtt.python/blob/master/ChangeLog.txt)
- [Commits](eclipse-paho/paho.mqtt.python@v1.6.0...v2.1.0)

---
updated-dependencies:
- dependency-name: paho-mqtt
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

pyproject.toml

@@ -81,4 +81,4 @@ dev = [
     "types-paho-mqtt",
 ]
 vision = ["opencv-python-headless >=4,<5"]
-mqtt = ["paho-mqtt >=1.6,<2"]
+mqtt = ["paho-mqtt >=2.1.0,<3"]