Change pytest plugin to use the same importer as other components

[ogenstad]

Fixes #166

[codecov]

Codecov Report

Attention: Patch coverage is 42.85714% with 8 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
infrahub_sdk/pytest_plugin/items/base.py	50.00%	4 Missing ⚠️
infrahub_sdk/pytest_plugin/items/check.py	33.33%	2 Missing ⚠️
...frahub_sdk/pytest_plugin/items/python_transform.py	33.33%	2 Missing ⚠️

@@             Coverage Diff             @@
##           develop     #171      +/-   ##
===========================================
- Coverage    65.47%   65.43%   -0.04%     
===========================================
  Files           81       81              
  Lines         7249     7259      +10     
  Branches      1407     1409       +2     
===========================================
+ Hits          4746     4750       +4     
- Misses        2116     2122       +6     
  Partials       387      387              

Flag	Coverage Δ
python-3.10	43.69% <0.00%> (-0.07%)	⬇️
python-3.11	43.69% <0.00%> (-0.07%)	⬇️
python-3.12	43.69% <0.00%> (-0.07%)	⬇️
python-3.13	43.69% <0.00%> (-0.07%)	⬇️
python-3.9	42.80% <0.00%> (-0.06%)	⬇️
python-filler-3.12	24.45% <42.85%> (+0.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
infrahub_sdk/_importer.py	74.28% <ø> (ø)
infrahub_sdk/pytest_plugin/items/check.py	44.44% <33.33%> (-1.02%)	⬇️
...frahub_sdk/pytest_plugin/items/python_transform.py	40.81% <33.33%> (-0.86%)	⬇️
infrahub_sdk/pytest_plugin/items/base.py	62.50% <50.00%> (-3.13%)	⬇️