Update dependencies and fix test issues

[callumforrester]

• Relock dependencies
• Fix compatibility issues with pytest-asyncio 0.19.0

[callumforrester]

There are also issues with the system test processes, may have to wait for @coretl to look at potential Python IOC issues

[codecov[bot]]

Codecov Report

Merging #71 (56dcd2b) into master (215582f) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #71   +/-   ##
=======================================
  Coverage   98.55%   98.55%           
=======================================
  Files          65       65           
  Lines        2082     2082           
=======================================
  Hits         2052     2052           
  Misses         30       30           

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[callumforrester]

@garryod only in a couple of cases, have updated