message: remove null fields from output abi
diff: @@ -358,8 +358,18 @@ export class Compiler {
  ...state.composerOutput.abi,
  };
  + const filteredAbi: Record<string, unknown> = { ...abi };
  +
  + Object.keys(filteredAbi).forEach((key) => {
  + const value = filteredAbi[key];
  +
  + if (value === null || value === undefined) {
  + delete filteredAbi[key];
  + }
  + });
  +
  const info: WrapManifest = {
  - abi: { ...abi },
  + abi: filteredAbi,
  name: manifest.name,
  type: (await this._isInterface()) ? "interface" : "wasm",
  version: "0.0.1",
  