Add paho-mqtt as a requirement in manifest.json

[chishm]

Add a requirement on the external package paho-mqtt so that Home Assistant will install it when trying to setup ha-dyson for the first time.

I've not put version restrictions in because I don't know what is/isn't compatible, but I found it worked with paho-mqtt==1.6.1.

[codyc1515]

Did you see an error because of not having this?

[chishm]

I did indeed. When I tried to add the Dyson integration following the [setup instructions](https://github.com/libdyson-wg/ha-dyson#setup), HA showed an error on screen saying it couldn't launch the config flow (sorry, I can't remember the exact error) and had an exception in the logs failing to import paho.mqtt, which clued me into the fact it was missing. I added the requirements to my installed ha-dyson custom component and it worked after that.

[dotvezz]

@chishm huh, this is super interesting and I'm honestly surprised this hasn't popped up before. Needless to say, it makes perfect sense to add paho-mqtt as an explicit requirement so I'll definitely do it.

I wonder if something changed with new versions of Home Assistant; I think it used to be in the dep tree of a basic installation, and it's still in the docker image for example: (edit: But I noticed it's not included when I do a normal installation on Debian. Not sure if that's really new or it's always been that way, but I kinda suspect it's new.)

> docker run --rm -it homeassistant/home-assistant pip show paho-mqtt
Name: paho-mqtt
Version: 1.6.1
Summary: MQTT version 5.0/3.1.1 client class
Home-page: http://eclipse.org/paho
Author: Roger Light
Author-email: roger@atchoo.org
License: Eclipse Public License v2.0 / Eclipse Distribution License v1.0
Location: /usr/local/lib/python3.11/site-packages
Requires: 
Required-by: aiomqtt, ibmiotf, pyeconet, pyezviz, pysmappee, python-roborock, roombapy, tuya-iot-py-sdk

[dotvezz]

Thanks for the PR! Merged and I'll do a release tonight.

[chishm]

I wonder if something changed with new versions of Home Assistant; I think it used to be in the dep tree of a basic installation, and it's still in the docker image for example: (edit: But I noticed it's not included when I do a normal installation on Debian. Not sure if that's really new or it's always been that way, but I kinda suspect it's new.)

I'm not sure if something has changed (this is my first time installing ha-dyson), but it sounds like you've managed to replicate my setup. To be exact, I run HA in its own Python venv on Ubuntu, and I don't use anything else that uses mqtt.

Thanks for the PR! Merged and I'll do a release tonight

You're welcome, and thanks for the careful consideration and merge.