[MetaSchedule] Skip custom_rule in case of None

[apeskov]

Custom rule mechanics allows to have "schedule_rule" attribute equals "None". This value will be ignored by ApplyCustomRuleNode. But also this block will be ignore by all other rules. It happens because of improper check in PostOrderApplyNode.

This patch allows to use regular rules in case of schedule_rule=="None".

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• cc @ibsidorenko _{See #10317 for details}

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[Hzfengsy]

cc @junrushao

[apeskov]

@junrushao could you please take a look. In your previous patch #13195 with refactoring of custom rules you already had a discussion with @masahi about auto tensorization issue.

But there is an another aspect. In case of schedule_rule == "None", ApplyCustomRule and sch->Unannotate will not be called. So block will not be processed by any schedule rule never. I'm not sure if it was in the design.

[junrushao]

I vaguely recall that there is a reason that we use custom_rule: None, which means we wanted to design space generator to intentionally skip a block. My assumption was that if we have a good usecase if we want the generator not to skip, then perhaps we could unannotate the block first - but I'm happy to change my mind if the situation above has been taken good consideration