PatAlgos: use python3 in unit test

[smuzaffar]

This is needed in order to drop the next set of python2 based modules ( cms-sw/cmsdist#7112 ).
These are technical changes and should not break any thing as unit tests are working in PY3 IBs where python is python3.

[smuzaffar]

please test

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-34473/23926

• This PR adds an extra 12KB to repository

• There are other open Pull requests which might conflict with changes you have proposed:

  • File PhysicsTools/PatAlgos/test/runtests.sh modified in PR(s): move a few unit tests to python3 #34470

[cmsbuild]

A new Pull Request was created by @smuzaffar (Malik Shahzad Muzaffar) for master.

It involves the following packages:

• PhysicsTools/PatAlgos (reconstruction)

@perrotta, @jpata, @slava77 can you please review it and eventually sign? Thanks.
@mmarionncern, @gouskos, @JyothsnaKomaragiri, @ahinzmann, @schoef, @rappoccio, @swozniewski, @jdamgov, @jdolen, @nhanvtran, @gkasieczka, @clelange, @emilbols, @hatakeyamak, @mbluj, @gpetruc, @andrzejnovak, @mariadalfonso, @seemasharmafnal this is something you requested to watch as well.
@silviodonato, @dpiparo, @qliphy, @perrotta you are the release manager for this.

cms-bot commands are listed here

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-0c159d/16778/summary.html
COMMIT: 1d8b172
CMSSW: CMSSW_12_0_X_2021-07-13-1100/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/34473/16778/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: 38
• DQMHistoTests: Total histograms compared: 2786302
• DQMHistoTests: Total failures: 1
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 2786279
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 37 files compared)
• Checked 160 log files, 37 edm output root files, 38 DQM output files
• TriggerResults: no differences found

[perrotta]

+reconstruction

• Technical, jenkins tests pass
• The change in PhysicsTools/PatAlgos/test/runtests.sh overlaps with the identical one in move a few unit tests to python3 #34470

[cmsbuild]

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

[qliphy]

+1