[biomin] reducde testing time new TEnd is set to 1e5 for tests

exercises/exercise-biomineralization/CMakeLists.txt

 # executables for exercisebiomin
 dune_add_test(NAME exercisebiomin
-              SOURCES exercisebiomin.cc)
+              SOURCES exercisebiomin.cc
+              CMD_ARGS -TimeLoop.TEnd 1e5)
 
 # add tutorial to the common target
 add_dependencies(test_exercises exercisebiomin)

exercises/solution/exercise-biomineralization/CMakeLists.txt

 # executables for exercisebiomin
 dune_add_test(NAME exercisebiomin_solution
-              SOURCES exercisebiomin.cc)
+              SOURCES exercisebiomin.cc
+              CMD_ARGS -TimeLoop.TEnd 1e5)
 
 # add tutorial to the common target
 add_dependencies(test_exercises exercisebiomin_solution)