fix(typescript): Check whether the method is abstract when checking is_overload (#9678)

**Related issue:**

 - Closes #9656

Author: CPunisher

.changeset/fair-maps-move.md

@@ -0,0 +1,6 @@
+---
+swc_core: patch
+swc_typescript: patch
+---
+
+fix(typescript): Check whether the method is abstract when checking `is_overload`

crates/swc_typescript/src/fast_dts/mod.rs

@@ -758,7 +758,7 @@ impl FastDts {
                     }
                 }
                 ClassMember::Method(method) => {
-                    let is_overload = method.function.body.is_none();
+                    let is_overload = method.function.body.is_none() && !method.is_abstract;
                     if !prev_is_overload || is_overload {
                         prev_is_overload = is_overload;
                         true

crates/swc_typescript/tests/fast_dts_deno.rs

@@ -218,6 +218,26 @@ fn dts_class_decl_prop_infer_test() {
     );
 }
 
+#[test]
+fn dts_class_abstract_method_test() {
+    transform_dts_test(
+        r#"export abstract class Manager {
+    protected abstract A(): void;
+    protected B(): void {
+        console.log("B");
+    }
+    protected C(): void {
+        console.log("B");
+    }
+}"#,
+        r#"export declare abstract class Manager {
+    protected abstract A(): void;
+    protected B(): void;
+    protected C(): void;
+}"#,
+    );
+}
+
 #[test]
 fn dts_var_decl_test() {
     transform_dts_test(