docs(lambda-python): Update default value for BundlingOptions.outputPathSuffix (#18231)

The current default value of `'''` is incorrect, and also causing the generated python for this module to have incorrect syntax, since `'''` is the mult-line comment delimiter in python. 


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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: madeline-k

packages/@aws-cdk/aws-lambda-python/lib/types.ts

@@ -6,9 +6,9 @@ import { AssetHashType, DockerImage } from '@aws-cdk/core';
  */
 export interface BundlingOptions {
   /**
-   * Output path suffix ('python' for a layer, '' otherwise)
+   * Output path suffix: the suffix for the directory into which the bundled output is written.
    *
-   * @default '''
+   * @default - 'python' for a layer, empty string otherwise.
    */
   readonly outputPathSuffix?: string;