fix: enable souremap building

Author: VividLemon

packages/bootstrap-vue-3/vite.config.ts

@@ -8,6 +8,7 @@ import dts from 'vite-plugin-dts'
 
 const config = defineConfig({
   build: {
+    sourcemap: true,
     minify: true,
     lib: {
       entry: resolve(__dirname, 'src/BootstrapVue.ts'),