Remove the FluxTracerType option from configs/Default.yml

[hyungyukang]

This PR removes the FluxTracerType option from configs/Default.yml (added by d94289c40f4e362a in OCT 2024), since it is no longer used anywhere in Omega.

Checklist

• Linting
  • Pre-commit run locally
• Building
  • CMake build does not produce any new warnings from changes in this PR
• Testing
  • Add a comment to the PR titled Testing with the following:
    • Which machines CTest unit tests
      have been run on and indicate that are all passing.
    • The Polaris omega_pr test suite
      has passed, using the Polaris e3sm_submodules/Omega baseline
    • Document machine(s), compiler(s), and the build path(s) used for -p for both the baseline (Polaris e3sm_submodules/Omega) and the PR build
    • Indicate "All tests passed" or document failing tests

[hyungyukang]

Testing

CTest unit tests

• Machine: frontier
• Compiler: craygnu,craygnu-mphipcc
• Build type: Release
• Result: All tests passed

Polaris omega_pr regression suite

• Baseline build (-p): /lustre/orion/cli115/proj-shared/hgkang/E3SM/OMEGA/Polaris/Polaris_main_260418/e3sm_submodules/Omega
• Baseline workdir (-w): /lustre/orion/cli115/proj-shared/hgkang/E3SM/OMEGA/Polaris/work/pr_suite/260422_removeOption_PR/baseline_omega
• PR build (-p): /lustre/orion/cli115/proj-shared/hgkang/E3SM/OMEGA/Polaris/Polaris_main_260418/e3sm_submodules/Omega_hyun_removeFluxPR
• PR workdir (-w): /lustre/orion/cli115/proj-shared/hgkang/E3SM/OMEGA/Polaris/work/pr_suite/260422_removeOption_PR/branch_omega
• Machine/partition: frontier
• Compiler/build type: craygnu
• Result: All tests passed
• Logs (if applicable): /lustre/orion/cli115/proj-shared/hgkang/E3SM/OMEGA/Polaris/work/pr_suite/260422_removeOption_PR/branch_omega/polaris_omega_pr.o4446604

[brian-oneill]

Config option was removed in #316 then accidentally reintroduced to Default.yml while resolving conflicts in #328. Approved by inspection

[sbrus89]

Passes all omega_pr tests on pm-cpu`:

Polaris omega_pr suite

• Baseline workdir: /global/homes/s/sbrus/scratch/polaris_vert_vel_halo_fix_omega_pr_baseline
• Baseline build: /global/homes/s/sbrus/scratch/polaris_vert_vel_halo_fix_omega_pr_baseline/build
• PR build: /global/homes/s/sbrus/scratch/polaris_remove_tracer_type_omega_pr/build
• PR workdir: /global/homes/s/sbrus/scratch/polaris_remove_tracer_type_omega_pr
• Machine: pm-cpu
• Compiler: gnu
• Build type: Release
• Log: not found
• Result: All tests passed