refactor!: Remove mean reduction from MultiEigenStepperLoop

[andiwand]

After #3521 we also want to change the default and remove the weighted mean reduction as it is unstable.

This pull request primarily focuses on removing the WeightedComponentReducerLoop struct and its associated functionality from the MultiEigenStepperLoop class and its tests. The changes simplify the codebase by eliminating the weighted component reduction logic and replacing it with the MaxWeightReducerLoop.

Removal of WeightedComponentReducerLoop:

• Core/include/Acts/Propagator/MultiEigenStepperLoop.hpp: Removed the WeightedComponentReducerLoop struct and its methods, which were responsible for reducing the multicomponent state by summing weighted values.

Replacement with MaxWeightReducerLoop:

• Core/include/Acts/Propagator/MultiEigenStepperLoop.hpp: Updated the MultiEigenStepperLoop class to use MaxWeightReducerLoop instead of WeightedComponentReducerLoop as the default component reducer.

Test updates:

• Tests/UnitTests/Core/Propagator/MultiStepperTests.cpp: Removed the test case for WeightedComponentReducerLoop, which validated the position and direction calculations using weighted sums.

[github-actions]

📊: Physics performance monitoring for 6c14959

Full contents

physmon summary

• ✅ Particles fatras
• ✅ Particles geant4
• ✅ Particles ttbar
• ✅ Vertices ttbar
• ✅ Truth tracking (KF)
• ✅ Truth tracking (GSF)
• ✅ Truth tracking (GX2F)
• ✅ CKF | trackfinding | single muon | truth smeared seeding
• ✅ Track Summary CKF | trackfinding | single muon | truth smeared seeding
• ✅ Seeding trackfinding | single muon | truth estimated seeding
• ✅ CKF | trackfinding | single muon | truth estimated seeding
• ✅ Track Summary CKF | trackfinding | single muon | truth estimated seeding
• ✅ Seeding trackfinding | single muon | default seeding
• ✅ CKF | trackfinding | single muon | default seeding
• ✅ Track Summary CKF | trackfinding | single muon | default seeding
• ✅ Seeding trackfinding | single muon | orthogonal seeding
• ✅ CKF | trackfinding | single muon | orthogonal seeding
• ✅ Track Summary CKF | trackfinding | single muon | orthogonal seeding
• ✅ Seeding trackfinding | 4 muon x 50 vertices | default seeding
• ✅ CKF | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Track Summary CKF | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Ambisolver | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ IVF notime | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ AMVF gauss notime | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ AMVF grid time | trackfinding | 4 muon x 50 vertices | default seeding
• ✅ Seeding trackfinding | ttbar with 200 pileup | default seeding
• ✅ CKF | trackfinding | ttbar with 200 pileup | default seeding
• ✅ Track Summary CKF | trackfinding | ttbar with 200 pileup | default seeding
• ✅ Ambisolver | trackfinding | ttbar with 200 pileup | default seeding
• ✅ AMVF gauss notime | trackfinding | ttbar with 200 pileup | default seeding
• ✅ AMVF grid time | trackfinding | ttbar with 200 pileup | default seeding

[benjaminhuth]

Thanks for having this in mind!

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[acts-project-service]

✅ Athena integration test results [dd33d4c]

✅ All tests successful

status	job	report
🟢	report_pull_request
🟢	run_art_test: test_data18_13TeV_1000evt
🟢	run_art_test: test_ttbarPU40_reco
🟢	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
🟢	test_ActsDumpGeometryIdentifiers
🟢	test_ActsCheckObjectCountsCachedWorkflow
🟢	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_unit_tests