QC-1287 Fix Mergers latency optimization with RoundRobin processing

[knopers8]

The optimization was correctly working when we split a range of InputSpecs between different Mergers in a layer, but not when they are time-pipelined. In the commit, we modify the expected number of input messages per cycle to include time-pipeline parameter in the previous and current layer.

[github-actions]

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[Barthelemy]

thank yous

[alibuild]

Error while checking build/O2/fullCI_slc9 for 2c012d9 at 2025-05-26 17:59:

## sw/BUILD/O2Physics-latest/log
Error in cling::AutoLoadingVisitor::InsertIntoAutoLoadingState:
Error in cling::AutoLoadingVisitor::InsertIntoAutoLoadingState:
Error in cling::AutoLoadingVisitor::InsertIntoAutoLoadingState:
Error in cling::AutoLoadingVisitor::InsertIntoAutoLoadingState:
Error in cling::AutoLoadingVisitor::InsertIntoAutoLoadingState:
Error in cling::AutoLoadingVisitor::InsertIntoAutoLoadingState:


## sw/BUILD/O2-full-system-test-latest/log
Detected critical problem in logfile digi.log
digi.log:[21480:internal-dpl-ccdb-backend]: [17:59:44][ERROR] Exception while running: Fatal error. Rethrowing.
digi.log-[21480:internal-dpl-ccdb-backend]: [17:59:44][FATAL] Unhandled o2::framework::runtime_error reached the top of main of o2-sim-digitizer-workflow, device shutting down. Reason: Fatal error
[21480:internal-dpl-ccdb-backend]: [17:59:42][ERROR] CCDBDownloader CURL transfer error - Timeout was reached
[21480:internal-dpl-ccdb-backend]: [17:59:42][ERROR] CcdbDownloader finished transfer http://alice-ccdb.cern.ch/PHS/Config/RecoParams for 1550600800000 (agent_id: alimetal01.cern.ch-1748275163-vGJD0a) with http code: 0
[21480:internal-dpl-ccdb-backend]: [17:59:42][ERROR] File PHS/Config/RecoParams could not be retrieved. No more hosts to try.
[21480:internal-dpl-ccdb-backend]: [17:59:42][FATAL] Unable to find CCDB object PHS/Config/RecoParams/1550600800000
[21480:internal-dpl-ccdb-backend]: [17:59:44][ERROR] Exception while running: Fatal error. Rethrowing.
[21480:internal-dpl-ccdb-backend]: [17:59:44][FATAL] Unhandled o2::framework::runtime_error reached the top of main of o2-sim-digitizer-workflow, device shutting down. Reason: Fatal error
[ERROR] Workflow crashed - PID 21480 (internal-dpl-ccdb-backend) did not exit correctly however it's not clear why. Exit code forced to 128.


## sw/BUILD/o2checkcode-latest/log
--
========== List of errors found ==========
++ GRERR=0
++ grep -v clang-diagnostic-error error-log.txt
++ grep ' error:'
++ GRERR=1
++ [[ 1 == 0 ]]
++ mkdir -p /sw/INSTALLROOT/6460ab83e8ed9deaf1c66fb9dd232a70379cdef6/slc9_x86-64/o2checkcode/1.0-local147/etc/modulefiles
++ cat
--

Full log here.