Remove call to syntax extensions in `where` clause
Remove call to syntax extensions in `where` clause

I am not sure if this call was useful. Removing it does not break any
test.

Zimmi48/coq,SkySkimmer/coq,coq/coq,SkySkimmer/coq,coq/coq,Zimmi48/coq,Zimmi48/coq,coq/coq,ejgallego/coq,Zimmi48/coq,SkySkimmer/coq,ejgallego/coq,ejgallego/coq,SkySkimmer/coq,coq/coq,ejgallego/coq