Grep for "OperationContext* const opCtx" and change to "OperationContext* opCtx" in function parameters in the index catalog related files. Also convert any other function parameters that have const pointers into regular pointers – OperationContext is just the easiest thing to grep for to find the relevant files.

This change is to make the function parameters stylistically consistent with the rest of the codebase; and to mitigate seeing and copying the '* const ' paradigm into new code, as has been done already.

We're only proposing this change for declarations, not definitions.