Fix workflow for changing experiment

[NicolaCourtier]

Description

Fix for issue #233. The current function was not being set during the call to set_params unless unmatched_parameters were present.

[codecov]

Codecov Report

Attention: Patch coverage is 95.65217% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 94.30%. Comparing base (2b238e4) to head (f2425ad).
Report is 21 commits behind head on develop.

Files	Patch %	Lines
pybop/models/base_model.py	93.33%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #240      +/-   ##
===========================================
+ Coverage    94.29%   94.30%   +0.01%     
===========================================
  Files           33       33              
  Lines         1753     1757       +4     
===========================================
+ Hits          1653     1657       +4     
  Misses         100      100              

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

[BradyPlanden]

Looks great — thanks for the fast bugfix @NicolaCourtier! A few small suggestions, happy for you to merge when ready.