fix(gx2f): forward propagation error

[AJPfleger]

Somehow the GX2F was so perfect, that no errors occurred until I got today

terminate called after throwing an instance of 'std::bad_variant_access'
 what():  std::get: wrong index for variant

[github-actions]

📊: Physics performance monitoring for fd13678

Full contents

physmon summary

• ✅ CKF truth_smeared
• ✅ IVF truth_smeared
• ✅ AMVF truth_smeared
• ✅ Track Summary CKF truth_smeared
• ✅ Seeding truth_estimated
• ✅ CKF truth_estimated
• ✅ IVF truth_estimated
• ✅ AMVF truth_estimated
• ✅ Track Summary CKF truth_estimated
• ✅ Seeding seeded
• ✅ CKF seeded
• ✅ IVF seeded
• ✅ AMVF seeded
• ✅ AMVF (+grid seeder) seeded
• ✅ Track Summary CKF seeded
• ✅ Seeding orthogonal
• ✅ CKF orthogonal
• ✅ IVF orthogonal
• ✅ AMVF orthogonal
• ✅ Track Summary CKF orthogonal
• ✅ Ambisolver seeded
• ✅ Ambisolver orthogonal
• ✅ Seeding ttbar
• ✅ CKF ttbar
• ✅ Ambisolver
• ✅ Track Summary CKF ttbar
• ✅ AMVF ttbar
• ✅ AMVF (+grid seeder) ttbar
• ✅ Truth tracking (GSF)
• ✅ Truth tracking
• ✅ Truth tracking (GX2F)
• ✅ Particles fatras
• ✅ Particles geant4

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 3 lines in your changes missing coverage. Please review.

Project coverage is 47.31%. Comparing base (06c2b63) to head (fd13678).
Report is 267 commits behind head on main.

Files with missing lines	Patch %	Lines
...nclude/Acts/TrackFitting/GlobalChiSquareFitter.hpp	0.00%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3296      +/-   ##
==========================================
- Coverage   47.31%   47.31%   -0.01%     
==========================================
  Files         512      512              
  Lines       30434    30437       +3     
  Branches    14793    14795       +2     
==========================================
  Hits        14400    14400              
- Misses       5402     5404       +2     
- Partials    10632    10633       +1     

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[acts-project-service]

🔴 Athena integration test results [1e0f2f1]

🔴 Some tests have failed!

Please investigate the pipeline!

status	job	report
🟢	run_unit_tests
🟢	test_ActsDumpGeometryIdentifiers
🟢	test_ActsCheckObjectCountsWorkflow
🟢	test_ActsEFTrackFit
🟢	test_ActsPersistifySeeds
🟢	test_ActsBenchmarkWithSpot
🟢	test_ActsAnalogueClustering
🟢	test_ActsWorkflowHeavyIons
🟢	test_ActsWorkflowFastTracking
🟢	test_ActsWorkflowCached
🟢	test_ActsWorkflow
🟢	test_ActsValidateAmbiguityResolution
🟢	test_ActsValidateResolvedTracks
🟢	test_ActsValidateTracks
🟢	test_ActsValidateActsCoreSpacePoints
🟢	test_ActsValidateActsSpacePoints
🟢	test_ActsValidateSeeds
🟢	test_ActsValidateOrthogonalSeeds
🟢	test_ActsValidateClusters
🟢	test_ActsPersistifyEDM
🟢	test_ActsGSFRefitting
🟢	test_ActsKfRefitting
🟢	test_ActsExtrapolationAlgTest
🟢	test_ActsITkTest
🟢	run_workflow_tests_run4_mc
🟢	run_workflow_tests_run2_mc
🟢	run_workflow_tests_run2_data
🔴	run_workflow_tests_run3_mc
🟢	run_workflow_tests_run3_data
🟢	run_art_test: test_data18_13TeV_1000evt
🟢	run_art_test: test_ttbarPU40_reco