gh: e2e-upgrade: clean up skip-include-conn-disrupt-test-ns-traffic flag
When using conn-disrupt-test-check with the tests option, none of the disruptivity tests are included. So we don't need to explicitly skip the ns-disruptivity test either.
When using conn-disrupt-test-check with the tests option, none of the disruptivity tests are included. So we don't need to explicitly skip the ns-disruptivity test either.