Create a blank user config file before running tests

Previously we only removed the properties file but some tests
could touch other parts of the user config so remove it all
and create a blank file to ensure the environment is clean.
Refs #22063

(cherry picked from commit 07c1513f)

buildconfig/Jenkins/buildscript

@@ -280,9 +280,11 @@ fi
 ###############################################################################
 # Run the unit tests
 ###############################################################################
-# Remove any Mantid.user.properties file
-userprops=~/.mantid/Mantid.user.properties
-rm -f $userprops
+# Prevent race conditions when creating the user config directory
+userconfig_dir=$HOME/.mantid
+rm -fr $userconfig_dir
+mkdir -p $userconfig_dir
+touch $userconfig_dir/Mantid.user.properties
 $CTEST_EXE -j${BUILD_THREADS:?} --schedule-random --output-on-failure
 
 ###############################################################################

buildconfig/Jenkins/buildscript.bat

@@ -157,10 +157,14 @@ if ERRORLEVEL 1 exit /B %ERRORLEVEL%
 :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
 :: Run the tests
 :::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::
-:: Remove the user properties file just in case anything polluted it
+:: Remove any user configuration and create a blank user properties file
+:: This prevents race conditions when creating the user config directory
 set USERPROPS=bin\%BUILD_CONFIG%\Mantid.user.properties
 del %USERPROPS%
-
+set CONFIGDIR=%APPDATA%\mantidproject\mantid
+rmdir /S /Q %CONFIGDIR%
+mkdir %CONFIGDIR%
+call cmake.exe -E touch %USERPROPS%
 call ctest.exe -C %BUILD_CONFIG% -j%BUILD_THREADS% --schedule-random --output-on-failure
 if ERRORLEVEL 1 exit /B %ERRORLEVEL%