fix: Convert vendor/pezkuwi-subxt from submodule to regular directory

vendor/pezkuwi-subxt/codegen/src/api/errors.rs

@@ -0,0 +1,36 @@
+// Copyright 2019-2025 Parity Technologies (UK) Ltd.
+// This file is dual-licensed as Apache-2.0 or GPL-3.0.
+// see LICENSE for license details.
+
+use proc_macro2::TokenStream as TokenStream2;
+use quote::quote;
+use scale_typegen::TypeGenerator;
+use pezkuwi_subxt_metadata::PalletMetadata;
+
+use super::CodegenError;
+use scale_typegen::typegen::ir::ToTokensWithSettings;
+
+/// Generate error type alias from the provided pallet metadata.
+pub fn generate_error_type_alias(
+    type_gen: &TypeGenerator,
+    pallet: &PalletMetadata,
+) -> Result<TokenStream2, CodegenError> {
+    let Some(error_ty) = pallet.error_ty_id() else {
+        return Ok(quote!());
+    };
+
+    let error_type = type_gen
+        .resolve_type_path(error_ty)?
+        .to_token_stream(type_gen.settings());
+    let error_ty = type_gen.resolve_type(error_ty)?;
+    let docs = &error_ty.docs;
+    let docs = type_gen
+        .settings()
+        .should_gen_docs
+        .then_some(quote! { #( #[doc = #docs ] )* })
+        .unwrap_or_default();
+    Ok(quote! {
+        #docs
+        pub type Error = #error_type;
+    })
+}