fix: shared Rsbuild plugins should run only once

[chenjiahan]

Summary

I found this issue when testing rsbuild-plugin-publint.

In Rsbuild, shared plugins will run only once. Take rsbuild-plugin-publint as an example, it uses api.onAfterBuild to trigger the linting, and this should only be triggered once per build, otherwise it will result in duplicate lint output.

// rsbuild.config.ts
export default {
  // this is a shared plugin
  plugins: [publintPlugin],
  environments: {
    client: {
      plugins: [clientOnlyPlugin],
    },
    server: {
      plugins: [serverOnlyPlugin],
    },
  },
};

Currently Rslib does not align with this behavior, the shared plugins are registered multiple times. After this PR, Rslib will be aligned with Rsbuild.

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

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[codspeed-hq]

CodSpeed Performance Report

Merging #552 will not alter performance

_{Comparing shared_plugin_1212 (1c7c718) with main (aa4c5f3)}

Summary

✅ 5 untouched benchmarks