[T/LIE] Slightly relax ctest's tolerance

Tests/Data/LIE/Mechanics/mohr_coulomb_load_path_nu0p3.prj

@@ -304,7 +304,7 @@
         <vtkdiff>
             <regex>out_mohr_coulomb_load_path_nu0p3_ts_(.*)_t_2.500000.vtu</regex>
             <field>stress_xy</field>
-            <absolute_tolerance>2.2e-3</absolute_tolerance>
+            <absolute_tolerance>2.6e-3</absolute_tolerance>
             <relative_tolerance>0</relative_tolerance>
         </vtkdiff>
         <vtkdiff>