remove explicit calls to PyQt5

[mariostieriansys]

We are on the verge of moving from Qt5 to Qt6

As part of this effort, we need to remove all the explicit calls to PyQt5 and use the qtpy wrapper, which adapts to the underlying Qt environment

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 50.00000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 80.53%. Comparing base (f71c77e) to head (e254138).

Files with missing lines	Patch %	Lines
...dynamicreporting/core/utils/report_download_pdf.py	0.00%	2 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #356   +/-   ##
=======================================
  Coverage   80.53%   80.53%           
=======================================
  Files          25       25           
  Lines        7163     7163           
  Branches     1347     1347           
=======================================
  Hits         5769     5769           
  Misses        976      976           
  Partials      418      418           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.