Add benchmark skip to examples

tox.ini

@@ -34,7 +34,7 @@ commands = pytest datashader -k "not test_tiles" -n logical --dist loadgroup --c
 description = Test that default examples run
 deps = .[examples, tests]
 commands = datashader fetch-data --path=examples --use-test-data
-           pytest -n logical --dist loadscope --nbval-lax examples
+           pytest -n logical --dist loadscope --nbval-lax examples --benchmark-skip
 # could add more, to test types of example other than nbs
 
 [_examples_extra]