Properly mark Meta.parse as public (#56931)

This is to remove the warning that the symbol is internal when checking
the docstring for `Meta.parse` since it’s in the documentation.

Author: christiangnrd

base/meta.jl

@@ -16,6 +16,8 @@ export quot,
        show_sexpr,
        @dump
 
+public parse
+
 using Base: isidentifier, isoperator, isunaryoperator, isbinaryoperator, ispostfixoperator
 import Base: isexpr