More fixes for stressGraphics

[couet]

This PR fixes :

https://lcgapp-services.cern.ch/root-jenkins/view/ROOT%20Nightly/job/root-nightly-master/LABEL=ROOT-debian10-i386,SPEC=default,V=master/lastCompletedBuild/testReport/junit/projectroot/test/test_stressgraphics/

[phsft-bot]

Starting build on ROOT-performance-centos8-multicore/soversion, ROOT-ubuntu2204/nortcxxmod, ROOT-ubuntu2004/python3, mac11/noimt, mac12arm/cxx20, windows10/default
How to customize builds

[phsft-bot]

Build failed on ROOT-ubuntu2204/nortcxxmod.
Running on root-ubuntu-2204-1.cern.ch:/home/sftnight/build/workspace/root-pullrequests-build
See console output.

Failing tests:

• projectroot.tmva.pymva.test.gtest_tmva_pymva_test_TestRModelParserPyTorch

[phsft-bot]

Build failed on ROOT-ubuntu2004/python3.
Running on root-ubuntu-2004-3.cern.ch:/home/sftnight/build/workspace/root-pullrequests-build
See console output.

Failing tests:

• projectroot.roottest.python.distrdf.dask.roottest_python_distrdf_dask_test_all

[github-actions]

Test Results

       10 files         10 suites   2d 0h 37m 9s ⏱️
  2 486 tests   2 485 ✔️ 0 💤 1 ❌
23 791 runs  23 790 ✔️ 0 💤 1 ❌

For more details on these failures, see this check.

Results for commit 35cc669.