Revert "feat: use Geant4TVUserParticleHandler by default (#44)"

[wdconinc]

Briefly, what does this PR introduce? Please link to any relevant presentations or discussions.

This reverts commit 6c595b9. It has too large implications in eic/containers#257 and needs additional pieces..

What is the urgency of this PR?

• High (please describe reason below)
• Medium
• Low

What kind of change does this PR introduce?

• Bug fix (issue: stuck on this in feat: npsim 1.5.0, patch dd4hep warning for Geant4TVUserParticleHandler containers#257)
• New feature (issue #__)
• Optimization (issue #__)
• Updated documentation
• other: __

Please check if any of the following apply

• This PR introduces breaking changes. Please describe changes users need to make below.
• This PR changes default behavior. Please describe changes below.
• AI was used in preparing this PR. Please describe usage below.

[wdconinc]

FYI @DraTeots

[github-actions]

Capybara summary for PR 64

• sim_dis_10x100_minQ2=1000_epic_craterlake
• sim_dis_10x100_minQ2=1_epic_craterlake
• sim_dis_18x275_minQ2=1000_epic_craterlake
• sim_dis_18x275_minQ2=1_epic_craterlake
• sim_dis_5x41_minQ2=1_epic_craterlake
• sim_e_1GeV_20GeV_epic_craterlake
• sim_pi_1GeV_20GeV_epic_craterlake
  ^{_{Last updated 2026-05-26T18:19-04:00 1b28d43}}