[PWGCF] update correction method and remove extra matrices histograms

[TGahlaut1]

No description provided.

[github-actions]

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

[alibuild]

Error while checking build/O2Physics/staging for 177afdc at 2026-08-28 10:39:

## sw/BUILD/O2Physics-latest/log
c++: fatal error: Killed signal terminated program cc1plus
c++: fatal error: Killed signal terminated program cc1plus
ninja: build stopped: subcommand failed.

Full log here.

[alibuild]

Error while checking build/O2Physics/code-check for 177afdc at 2026-08-28 13:57:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 1 errors and 1 warnings.'
Found 1 errors and 1 warnings.
++ [[ 1 -gt 0 ]]
++ cat /sw/BUILD/97deb76b8f229e17ee8df0b036367dcd769b32e6/O2Physics-code-check/errors.txt
PWGCF/EbyEFluctuations/Tasks/meanPtFlucId.cxx:60:8: error: constructor does not initialize these fields: ccdb [cppcoreguidelines-pro-type-member-init,-warnings-as-errors]
++ [[ 1 -gt 0 ]]
++ cat /sw/BUILD/97deb76b8f229e17ee8df0b036367dcd769b32e6/O2Physics-code-check/warnings.txt
PWGCF/EbyEFluctuations/Tasks/meanPtFlucId.cxx:255:7: warning: use auto when initializing with a template cast to avoid duplicating the type name [modernize-use-auto]
++ [[ 1 -gt 0 ]]
++ exit 1
--

Full log here.