[PWGEM] Fix includes

[vkucera]

No description provided.

[github-actions]

O2 linter results: ❌ 14 errors, ⚠️ 114 warnings, 🔕 23 disabled

[alibuild]

Error while checking build/O2Physics/code-check for 35d1fa4 at 2026-09-08 02:38:

## sw/BUILD/O2Physics-code-check-latest/log
--
========== List of issues found ==========
++ echo 'Found 6 errors and 3 warnings.'
Found 6 errors and 3 warnings.
++ [[ 6 -gt 0 ]]
++ cat /sw/BUILD/af4b14ee569e25562f013f93ff3c4d291593e2b0/O2Physics-code-check/errors.txt
PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx:65:8: error: constructor does not initialize these fields: ccdb [cppcoreguidelines-pro-type-member-init,-warnings-as-errors]
PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx:177:39: error: do not use static_cast to downcast from a base to a derived class; use dynamic_cast instead [cppcoreguidelines-pro-type-static-cast-downcast,-warnings-as-errors]
PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx:178:24: error: do not implicitly decay an array into a pointer; consider using gsl::array_view or an explicit cast instead [cppcoreguidelines-pro-bounds-array-to-pointer-decay,-warnings-as-errors]
PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx:296:65: error: the parameter 'fwdtrack' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param,-warnings-as-errors]
PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx:390:17: error: narrowing conversion from 'float' to 'int' [bugprone-narrowing-conversions,-warnings-as-errors]
PWGEM/Dilepton/Tasks/testPV.cxx:35:8: error: constructor does not initialize these fields: ccdb [cppcoreguidelines-pro-type-member-init,-warnings-as-errors]
++ [[ 3 -gt 0 ]]
++ cat /sw/BUILD/af4b14ee569e25562f013f93ff3c4d291593e2b0/O2Physics-code-check/warnings.txt
PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx:56:10: warning: inclusion of deprecated C++ header 'math.h'; consider using 'cmath' instead [modernize-deprecated-headers]
PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx:176:11: warning: do not declare C-style arrays, use 'std::array' instead [modernize-avoid-c-arrays]
PWGEM/Dilepton/TableProducer/skimmerPrimaryMuon.cxx:177:5: warning: use auto when initializing with a cast to avoid duplicating the type name [modernize-use-auto]
++ [[ 6 -gt 0 ]]
++ exit 1
--

Full log here.