Removed work-around in FindGeant4.cmake

[ihrivnac]

• Not needed with Geant4 versions 11.x

This addresses the JIRA issue O2-1242

[github-actions]

REQUEST FOR PRODUCTION RELEASES:
To request your PR to be included in production software, please add the corresponding labels called "async-" to your PR. Add the labels directly (if you have the permissions) or add a comment of the form (note that labels are separated by a ",")

+async-label <label1>, <label2>, !<label3> ...

This will add <label1> and <label2> and removes <label3>.

The following labels are available
async-2023-pbpb-apass4
async-2023-pp-apass4
async-2024-pp-apass1
async-2022-pp-apass7
async-2024-pp-cpass0
async-2024-PbPb-apass1
async-2024-ppRef-apass1
async-2024-PbPb-apass2
async-2023-PbPb-apass5

[alibuild]

Error while checking build/O2/fullCI_slc9 for c3774dd at 2025-09-08 04:00:

No log files found

Full log here.

[ihrivnac]

@sawenzel , the failures are unrelate to this PR. Can you merge ?

[sawenzel]

will merge once the CI is back to green

[sawenzel]

@ktf: MacOS ARM CI is failing in CCDB related code. Probably all PRs affected.

[ktf]

@singiamtel is looking into it.