message: feat(utxo-lib): compute getTapleafHash only once per signature
  Issue:
diff: @@ -58,6 +58,7 @@ export function getInputUpdate(
  if (!('controlBlock' in parsed)) {
  throw new Error(`keypath not implemented`);
  }
  + const leafHash = taproot.getTapleafHash(eccLib, parsed.controlBlock, parsed.pubScript);
  return {
  tapLeafScript: [
  {
  @@ -66,10 +67,7 @@ export function getInputUpdate(
  leafVersion: parsed.leafVersion,
  },
  ],
  - tapScriptSig: getPartialSigs().map((obj) => ({
  - ...obj,
  - leafHash: taproot.getTapleafHash(eccLib, parsed.controlBlock, parsed.pubScript),
  - })),
  + tapScriptSig: getPartialSigs().map((obj) => ({ ...obj, leafHash })),
  };
  }
  }
  