fix: avoid shared tsup config runtime import

Author: Shaw

plugins/tsup.plugin-packages.shared.ts

@@ -1,6 +1,5 @@
 import { existsSync, readdirSync } from "node:fs";
 import path from "node:path";
-import { defineConfig } from "tsup";
 
 function resolvePackageRoot(): string {
   if (typeof process.env.npm_package_json === "string") {
@@ -40,7 +39,7 @@ function collectSrcEntries(srcRoot: string): string[] {
 }
 
 /** Transpile workspace plugins/apps under `plugins/*` without bundling deps. */
-export default defineConfig({
+export default {
   entry: collectSrcEntries(path.join(resolvePackageRoot(), "src")),
   outDir: "dist",
   format: ["esm"],
@@ -56,4 +55,4 @@ export default defineConfig({
     options.packages = "external";
     return options;
   },
-});
+};