[PWGCF] Non-prompt flag for the filter2prong

[jaelpark]

No description provided.

[github-actions]

O2 linter results: ❌ 36 errors, ⚠️ 23 warnings, 🔕 0 disabled

[alibuild]

Error while checking build/O2Physics/o2 for 6afe062 at 2026-04-13 17:51:

## sw/BUILD/O2Physics-latest/log
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/PWGCF/TableProducer/filter2Prong.cxx:293:105: error: expected ':' before ')' token
/sw/SOURCES/O2Physics/slc9_x86-64-slc9_x86-64/0/PWGCF/TableProducer/filter2Prong.cxx:293:105: error: expected primary-expression before ')' token
ninja: build stopped: subcommand failed.

Full log here.

[vkucera]

@jaelpark Do not open a PR for review if you did not test it and it doesn't pass the formatting.