fix timeout for test_activation_ops_ipu (#45181)

Author: gglin001

python/paddle/fluid/tests/unittests/ipu/CMakeLists.txt

@@ -14,6 +14,7 @@ if(WITH_IPU)
   set_tests_properties(test_elemetwise_x_op_ipu PROPERTIES TIMEOUT 300)
   set_tests_properties(test_reduce_x_op_ipu PROPERTIES TIMEOUT 600)
   set_tests_properties(test_save_load_ipu PROPERTIES TIMEOUT 600)
+  set_tests_properties(test_activation_ops_ipu PROPERTIES TIMEOUT 600)
 
   add_subdirectory(custom_ops)