test(derive): No longer supporting some wrapped types

With the new `ArgMatches`, we need to know what the inner type is.

Unfortunately, #3142 didn't list use cases for this.  We dropped the
`Option` alias changing `T` but we still have a `Result` in there that
is aliased.

One potential workaround if people need it is if we add an attribute to
specify the `get_many::<T>` type.  This would also help with
`ArgAction::Count` to support more data types.

tests/derive/type_alias_regressions.rs

@@ -1,27 +1,13 @@
+//! Regression test to ensure that type aliases do not cause compilation failures.
 #![allow(deprecated)]
 
-/// Regression test to ensure that type aliases do not cause compilation failures.
-use std::str::FromStr;
-
 use clap::{Parser, Subcommand, ValueEnum};
 
 // Result type alias
 #[allow(dead_code)]
 type Result<T> = std::result::Result<T, Box<dyn std::error::Error>>;
 
-// Wrapper to use for Option type alias
-#[derive(Debug, PartialEq, Eq)]
-struct Wrapper<T>(T);
-
-impl<T: FromStr> FromStr for Wrapper<T> {
-    type Err = <T as FromStr>::Err;
-
-    fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
-        T::from_str(s).map(Wrapper)
-    }
-}
-
-type Option<T> = std::option::Option<Wrapper<T>>;
+type Option<T> = std::option::Option<T>;
 
 #[derive(Parser)]
 pub struct Opts {