Of course not, again such a law means that the government is mandating an official school policy, it is requiring the school to implement a religious action.
That’s something that clearly violates the principle of freedom of religion.
However if the parent body of an individual school decided upon their own to act in accordance with the majority of the particular school’s population in prayer policy, with the caveat that the minority population within that school is not required to attend or take part in any way.
I don’t see the difference. By allowing time for “prayer”, you are privileging specific religious practices over others.
If your argument is that the “prayer” should happen outside school, not during school hours, and organized by parents, not the government or teachers, I believe that would be legal today.
Wallace v. Jaffree discusses the issues with “voluntary” prayer.