Add missing phi width plots for pixels in IDPVM
Self-explanatory. Those missing plots are currently expected in the ART tests config, which are then reported as unsuccessful. See e.g. https://atlas-art-data.web.cern.ch/atlas-art-data/grid-output/master/Athena/x86_64-centos7-gcc11-opt/2023-02-27T2101/InDetPhysValMonitoring/test_mu100GeV_reco/dcube_last/