Update macOS buildscript to remove crash report files before running tests (#30985)

Also removes stale MantidPlot code we no longer need.

buildconfig/Jenkins/buildscript

@@ -391,14 +391,15 @@ fi
 # Prevent race conditions when creating the user config directory
 userconfig_dir=$HOME/.mantid
 rm -fr $userconfig_dir
-# Remove GUI qsettings files
+# Remove old application saved state & crash reports on mac.
+# If we don't do this then when a previous test has crashed macOS
+# will pop up a dialog box and wait for clicking okay. We are heavy
+# handed but builders tend not to be used for anything else.
 if [[ ${ON_MACOS} == true ]] ; then
-    rm -f $HOME/Library/Preferences/com.mantid.MantidPlot.plist
-    rm -f $HOME/Library/Preferences/org.mantidproject.MantidPlot.plist
-    rm -f "$HOME/Library/Saved Application State/org.mantidproject.MantidPlot.savedState/windows.plist"
-else
-    rm -f ~/.config/Mantid/MantidPlot.conf
+    rm -fr "$HOME/Library/Saved Application State/org.python.python"
+    rm -f $HOME/Library/Application\ Support/CrashReporter/*
 fi
+# Remove GUI qsettings files
 rm -f ~/.config/mantidproject/mantidworkbench.ini
 
 mkdir -p $userconfig_dir