⬆️ update workflows and project configuration

[burgholzer]

Description

This PR updates the workflow and general project configuration to the latest standards.
Anytime the CD workflow runs on a push to main, it uploads the resulting package to Test PyPI. This allows to battle test the packages before official releases.

Checklist:

• The pull request only contains commits that are related to it.
• I have added appropriate tests and documentation.
• I have made sure that all CI jobs on GitHub pass.
• The pull request introduces no new warnings and follows the project's style guidelines.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 75.8%. Comparing base (df0645b) to head (f8e22a3).
Report is 12 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main     #62   +/-   ##
=====================================
  Coverage   75.7%   75.8%           
=====================================
  Files        118     118           
  Lines       6242    6242           
  Branches     278     278           
=====================================
+ Hits        4731    4734    +3     
+ Misses      1511    1508    -3     

Flag	Coverage Δ
cpp	63.7% <ø> (ø)
python	79.9% <100.0%> (+<0.1%)	⬆️

Files with missing lines	Coverage Δ
src/mqt/qudits/quantum_circuit/circuit.py	89.3% <100.0%> (ø)
...um_circuit/components/extensions/matrix_factory.py	85.0% <100.0%> (ø)
...c/mqt/qudits/simulation/backends/stochastic_sim.py	91.6% <100.0%> (+6.2%)	⬆️