[anisaoshafi]

samlocal now prints a deprecation notice to stderr on every run. It points users to lstk sam and the migration guide. It reuses the notice structure from the localstack CLI (DEVX-1126).

============================================================================
  WARNING: 'samlocal' is deprecated. Use 'lstk sam' instead.
============================================================================

  'samlocal' no longer receives updates.

  Get started with 'lstk', the new LocalStack CLI:
  https://docs.localstack.cloud/aws/developer-tools/running-localstack/lstk/

  Switch your scripts and CI workflows to 'lstk sam':
  https://docs.localstack.cloud/aws/developer-tools/running-localstack/lstk/migration/#infrastructure-as-code

============================================================================

Continuing with 'samlocal'...

• Stdout stays clean, so piped output still works.
• DISABLE_DEPRECATION_NOTICE=1 hides the notice.
• Adds the same note to the README and bumps the version to 1.71.0.

Resolves DEVX-1168