refactor(core): reuse plugin directory names (#41754)

packages/core/src/config/plugin/source.ts

@@ -153,10 +153,12 @@ const scan = Effect.fn("ConfigPluginSource.scan")(function* (
   })
 })
 
+const sourceDirectories = ["plugin", "plugins"] as const
+
 function discoverDirectory(fs: FSUtil.Interface, directory: string) {
   return Effect.gen(function* () {
     const files = yield* fs
-      .scan("{plugin,plugins}/*.{ts,js}", {
+      .scan(`{${sourceDirectories.join(",")}}/*.{ts,js}`, {
         cwd: directory,
         absolute: true,
         include: "file",
@@ -168,8 +170,6 @@ function discoverDirectory(fs: FSUtil.Interface, directory: string) {
   })
 }
 
-const sourceDirectories = ["plugin", "plugins"] as const
-
 function isPluginSource(entries: readonly Entry[], file: string) {
   return entries.some(
     (entry) =>