[PWGHF] Add HFE event mixing and high-pT electron cut (TPC+EMCAL)

[rashigupt]

Implemented offline event mixing in TaskCorrelatorHfeHadron.cxx and added a high-pT cut in electron selection in ElectronSelectionWithTPCEMCal.cxx

[github-actions]

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

[vkucera]

Test your formatting before you make the PR ready for review.

[rashigupt]

Dear expert, please approve and merge the code

[rashigupt]

Dear Expert, if everything looks okay, please approve and merge the code.

[apalasciano]

Dear Rashi,
with offline ME, we usually refer to the computation of the ME distributions completely offline, as explained in this presentation.
I am not entirely sure that what you want to do with this process function will work, since you may be limited to mixing hfe and hadrons that belong to the same DF.
(In case you want to use the same strategy as other analyses, close this PR.)

[apalasciano]

Suggested change

	if (electron.timeStamp() == hadron.timeStamp()) {
	if (electron.timeStamp() == hadron.timeStamp() && hadron.gIndexCol() == electron.gIndexCol()) {

[apalasciano]

remove

[apalasciano]

remove this if statement

[alibuild]

Error while checking build/O2Physics/staging for 0676d7e at 2026-05-06 22:49:

## sw/BUILD/O2Physics-latest/log
CMake Error at /sw/slc9_x86-64/CMake/v4.1.4-2/share/cmake-4.1/Modules/CMakeTestCCompiler.cmake:67 (message):
    2026-05-06T22:49:32.765+0200 [70:139949333937792] [buildboxcommon_grpcretrier.cpp:177] [ERROR] Retry limit (0) exceeded for "ActionCache.GetActionResult()", last gRPC error was [14: failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:8085: Failed to connect to remote host: Connection refused]
    2026-05-06T22:49:32.765+0200 [70:139949333937792] [executioncontext.cpp:544] [ERROR] Error while querying action cache at "http://localhost:8085": 14: failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:8085: Failed to connect to remote host: Connection refused
    2026-05-06T22:49:32.766+0200 [70:139949333937792] [buildboxcommon_grpcretrier.cpp:177] [ERROR] Retry limit (0) exceeded for "FindMissingBlobs()", last gRPC error was [14: failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:8085: Failed to connect to remote host: Connection refused]
    2026-05-06T22:49:32.766+0200 [70:139949333937792] [executioncontext.cpp:908] [ERROR] Error while uploading resources to CAS at "http://localhost:8085": 14: failed to connect to all addresses; last error: UNKNOWN: ipv4:127.0.0.1:8085: Failed to connect to remote host: Connection refused
    ninja: build stopped: subcommand failed.

Full log here.

[rashigupt]

Dear Rashi, with offline ME, we usually refer to the computation of the ME distributions completely offline, as explained in this presentation. I am not entirely sure that what you want to do with this process function will work, since you may be limited to mixing hfe and hadrons that belong to the same DF. (In case you want to use the same strategy as other analyses, close this PR.)

Dear @apalasciano When I submit the code on Hyperloop and save the derived data, the corresponding derived dataset becomes very large, approximately 1 TB. Because of this, I am unable to use the “Save Slim Data” option effectively. Additionally, downloading a dataset of this size is quite difficult, while the standard derived dataset does not provide the final results needed for the analysis.

For this reason, I committed the code and would like to follow the same strategy that is being used in other analyses. However, if you have any alternative suggestions or recommendations, I would be very grateful for your help.
Best regards,
Rashi gupta