Declare Meta before using it in @intertypes

The `@intertypes` macro assigns `mod.Meta` without declaring it.
This was accidentally allowed in Julia 1.9/1.10 due to a dropped
error check, but will likely be disallowed again in Julia 1.11.
See JuliaLang/julia#54678.

This just declares it `global` (which is what happened implicitly
on Julia 1.10/1.11). That said, you may want a `Const` instead,
in which case you would need a different fix.

src/intertypes/julia.jl

@@ -379,6 +379,7 @@ macro intertypes(file, modexpr)
     end
     _ => error("expected a module expression, got $modexpr")
   end
+  push!(modexpr.args[3].args, :(global Meta))
   imports = Expr(:vect, [:($(Expr(:quote, name)) => $name.Meta) for name in imports]...)
   Expr(
     :toplevel,