[PWGUD] updated version for mc

[miedema-11]

A completed mc producer with new event selections

[github-actions]

O2 linter results: ❌ 0 errors, ⚠️ 1 warnings, 🔕 0 disabled

[alibuild]

Error while checking build/O2Physics/code-check for 87069ec at 2026-08-01 17:25:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 2 errors and 11 warnings.'
Found 2 errors and 11 warnings.
++ [[ 2 -gt 0 ]]
++ cat /sw/BUILD/cf737b1364a6f0426d16dc5d967200dca44c72a8/O2Physics-code-check/errors.txt
PWGUD/Tasks/flowMcUpc.cxx:899:10: error: Value stored to 'bc' during its initialization is never read [clang-analyzer-deadcode.DeadStores,-warnings-as-errors]
PWGUD/Tasks/flowMcUpc.cxx:899:10: error: unused variable 'bc' [clang-diagnostic-unused-variable,-warnings-as-errors]
++ [[ 11 -gt 0 ]]
++ cat /sw/BUILD/cf737b1364a6f0426d16dc5d967200dca44c72a8/O2Physics-code-check/warnings.txt
PWGUD/Tasks/flowMcUpc.cxx:867:81: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:874:24: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:876:27: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:878:27: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:880:29: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:901:35: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:904:27: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:908:33: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:917:166: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:919:43: warning: statement should be inside braces [readability-braces-around-statements]
PWGUD/Tasks/flowMcUpc.cxx:921:51: warning: statement should be inside braces [readability-braces-around-statements]
++ [[ 2 -gt 0 ]]
++ exit 1
--

Full log here.