message: Update deprecation message to include alternative.
diff: @@ -135,7 +135,7 @@ export async function loadConfig({
  }
  if (legacyKey) {
  Debug.warning(
  - `[Deprecation warning] Setting the key via ${legacyKeyEnvVar} is deprecated and will not be supported in future versions.`
  + `[Deprecation warning] Setting the key via ${legacyKeyEnvVar} is deprecated and will not be supported in future versions. Please use ${keyEnvVar} instead.`
  );
  }
  apiKey = key || legacyKey;
  