Enable masked_sparsity tutorial (#2714)

Author: svekars

.jenkins/validate_tutorials_built.py

@@ -31,7 +31,6 @@
     "advanced_source/ddp_pipeline",  # requires 4 gpus
     "advanced_source/usb_semisup_learn", # in the current form takes 140+ minutes to build - can be enabled when the build time is reduced
     "prototype_source/fx_graph_mode_ptq_dynamic",
-    "prototype_source/maskedtensor_sparsity", # Enable when fixed for 2.2
     "prototype_source/vmap_recipe",
     "prototype_source/torchscript_freezing",
     "prototype_source/nestedtensor",