macros: Add missing automatically_derived attributes

crates/ruma-macros/src/serde/deserialize_from_cow_str.rs

@@ -7,6 +7,7 @@ pub fn expand_deserialize_from_cow_str(ident: &Ident) -> syn::Result<TokenStream
     let ruma_common = import_ruma_common();
 
     Ok(quote! {
+        #[automatically_derived]
         impl<'de> #ruma_common::exports::serde::de::Deserialize<'de> for #ident {
             fn deserialize<D>(deserializer: D) -> ::std::result::Result<Self, D::Error>
             where

crates/ruma-macros/src/serde/enum_from_string.rs

@@ -68,6 +68,7 @@ pub fn expand_enum_from_string(input: &ItemEnum) -> syn::Result<TokenStream> {
     }
 
     Ok(quote! {
+        #[automatically_derived]
         impl<T> ::std::convert::From<T> for #enum_name
         where
             T: ::std::convert::AsRef<::std::primitive::str>