Revert mqtt 5.16.0

[hardillb]

Description

This was preventing the client from ever reconnecting

opened mqttjs/MQTT.js#2072 with upstream

Related Issue(s)

discovered locally

Checklist

• I have read the contribution guidelines
• Suitable unit/system level tests have been added and they pass
• Documentation has been updated
  • Upgrade instructions
  • Configuration details
  • Concepts
• Changes flowforge.yml?
  • Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production
• Link to Changelog Entry PR, or note why one is not needed.

Labels

• Includes a DB migration? -> add the area:migration label

[knolleary]

Should we pin exact for now rather than use ^ ?

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 77.50%. Comparing base (daa2133) to head (1c9f6b3).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #8679   +/-   ##
=======================================
  Coverage   77.50%   77.50%           
=======================================
  Files         469      469           
  Lines       25356    25356           
  Branches     6754     6754           
=======================================
  Hits        19652    19652           
  Misses       5704     5704           

Flag	Coverage Δ
backend	77.50% <ø> (ø)

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