DPL Analysis: write HistogramRegistry incrementally

[ktf]

This should reduce big spikes at the end of the processing when a large
HistogramRegistry is serialised.

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• -> DPL Analysis: write HistogramRegistry incrementally #14646
• DPL: allow closing a signpost interval with an error #14692

[github-actions]

REQUEST FOR PRODUCTION RELEASES:
To request your PR to be included in production software, please add the corresponding labels called "async-" to your PR. Add the labels directly (if you have the permissions) or add a comment of the form (note that labels are separated by a ",")

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[alibuild]

Error while checking build/O2/fullCI_slc9 for daa8075 at 2025-09-18 15:18:

## sw/BUILD/O2-full-system-test-latest/log
Detected critical problem in logfile reco_NOGPU.log


## sw/BUILD/o2checkcode-latest/log
--
========== List of errors found ==========
++ GRERR=0
++ grep -v clang-diagnostic-error error-log.txt
++ grep ' error:'
grep: error-log.txt: binary file matches
++ GRERR=1
++ [[ 1 == 0 ]]
++ mkdir -p /sw/INSTALLROOT/7e6f7431dfd5802267616562ce8df00fe0b99938/slc9_x86-64/o2checkcode/1.0-local328/etc/modulefiles
++ cat
--

Full log here.

[alibuild]

Error while checking build/O2/fullCI_slc9 for d20604b at 2025-09-22 19:11:

++ cp /sw/slc9_x86-64/O2/14646-slc9_x86-64-local1/compile_commands.json .
+++ python3 -c 'import json, os; print(os.path.commonpath([x["file"] for x in json.loads(open("compile_commands.json").read()) if "sw/BUILD" not in x["file"] and "G__" not in x["file"] and x["file"].endswith(".cxx")]))'
++ O2_SRC=/sw/SOURCES/O2/14646-slc9_x86-64/0
++ [[ -e /sw/SOURCES/O2/14646-slc9_x86-64/0/CMakeLists.txt ]]

Full log here.