Remove variadic! macro (pgcentralfoundation#2171)

Closes out the promise of pgcentralfoundation#1713

Author: workingjubilee

pgrx/src/aggregate.rs

@@ -342,9 +342,6 @@ where
     /// For multiple arguments, provide a tuple.
     ///
     /// Use [`pgrx::name!()`](crate::name) to set the SQL name of the argument.
-    ///
-    /// If the final argument is to be variadic, use [`pgrx::variadic`](crate::variadic). When used
-    /// with [`pgrx::name!()`](crate::name), it must be used **inside** the [`pgrx::name!()`](crate::name) macro.
     type Args;
 
     /// The types of the direct argument(s) to an ordered-set aggregate's `finalize`.

pgrx/src/fcinfo.rs

@@ -82,14 +82,6 @@ macro_rules! name {
     };
 }
 
-#[deprecated(since = "0.12.0", note = "try VariadicArray")]
-#[macro_export]
-macro_rules! variadic {
-    ($ty:ty) => {
-        $ty
-    };
-}
-
 /// Get a numbered argument for a `PG_FUNCTION_INFO_V1` function as the specified Rust type.
 ///
 /// # Safety