fix for TestDQMServicesDemo unit test [12.1.X]

[mmusich]

backport of #35921

PR description:

This PR tries to fix the DQM unit test TestDQMServicesDemo.
It looks like some API calls in DQM-related scripts needed to be adjusted after the switch from uproot-3 to uproot-4.
See #35868 for some more details.

PR validation:

The relevant unit test now passes.

if this PR is a backport please specify the original PR and why you need to backport that PR:

backport of #35921

[cmsbuild]

A new Pull Request was created by @mmusich (Marco Musich) for CMSSW_12_1_X.

It involves the following packages:

• DQMServices/Components (dqm)
• DQMServices/Demo (dqm)

@emanueleusai, @ahmad3213, @cmsbuild, @jfernan2, @pmandrik, @pbo0, @rvenditti can you please review it and eventually sign? Thanks.
@barvic this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

• Backported from fix for TestDQMServicesDemo unit test #35921

[mmusich]

test parameters:

• addpkg = DQM/Integration

[mmusich]

please test

[mmusich]

type bug-fix

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-fb14a8/20146/summary.html
COMMIT: 8d510da
CMSSW: CMSSW_12_1_X_2021-10-31-2300/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/35930/20146/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 0 differences found in the comparisons
• DQMHistoTests: Total files compared: 42
• DQMHistoTests: Total histograms compared: 2901440
• DQMHistoTests: Total failures: 0
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2901418
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 41 files compared)
• Checked 177 log files, 37 edm output root files, 42 DQM output files
• TriggerResults: no differences found

[jfernan2]

+1
Thank you @mmusich

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_12_1_X IBs (tests are also fine) and once validation in the development release cycle CMSSW_12_2_X is complete. This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[qliphy]

+1