chore: Change requirements syntax and upgrade celery

[iamareebjamal]

Part of #5854

[codecov]

Codecov Report

Merging #5944 into development will increase coverage by 0.12%.
The diff coverage is 83.33%.

@@               Coverage Diff               @@
##           development    #5944      +/-   ##
===============================================
+ Coverage        66.39%   66.52%   +0.12%     
===============================================
  Files              286      285       -1     
  Lines            13958    13905      -53     
===============================================
- Hits              9268     9250      -18     
+ Misses            4690     4655      -35

Impacted Files	Coverage Δ
app/api/helpers/tasks.py	17.59% <100%> (ø)	⬆️
app/__init__.py	86.3% <80%> (+2.21%)	⬆️
app/api/helpers/request_context_task.py

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[uds5501]

Only 'Order' import as PDF isn't working (which was broken before too), otherwise other celery tasks are successfully running