fix(tsdown): set fixedExtension to false in configuration

Author: honghuangdc

packages/create-soybean/template-vue-tsdown/tsdown.config.ts

@@ -13,5 +13,5 @@ export default defineConfig({
   external: ['vue'],
   sourcemap: false,
   minify: false,
-  fixedExtension: true
+  fixedExtension: false
 });

packages/create-soybean/tsdown.config.ts

@@ -6,5 +6,5 @@ export default defineConfig({
   clean: true,
   sourcemap: false,
   minify: false,
-  fixedExtension: true
+  fixedExtension: false
 });

tsdown.config.ts

@@ -7,5 +7,5 @@ export default defineConfig({
   dts: true,
   sourcemap: false,
   minify: false,
-  fixedExtension: true
+  fixedExtension: false
 });