Remove the schema checking from CrossJoinExec::try_new

[HaoYang670]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
https://github.com/apache/arrow-datafusion/blob/49166ea55f317722ab7a37fbfc253bcd497c1672/datafusion/core/src/physical_plan/joins/cross_join.rs#L67-L92
We don't need to check the schemas when doing cross join because the join key is always empty.

Describe the solution you'd like
Remove the checking and update the return type of the function. Also, it is better to rename the function as new

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.
We could not do this.

Additional context
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