fixed integ tests

[mohamedzeidan2021]

Issue #, if available:

Description of changes:
Fix integration test failures caused by deprecated JumpStart model IDs.

1. tests/integ/sagemaker/jumpstart/model/test_jumpstart_model.py

   • test_prepacked_jumpstart_model: Replaced model ID huggingface-txt2img-conflictx-complex-lineart with model-txt2img-stabilityai-stable-diffusion-v2-1-base. The previous model was deprecated in the JumpStart registry and raises
     DeprecatedJumpStartModelError.
   • test_jumpstart_model_register: Same model ID replacement. Also removed the pinned model_version="1.1.0" parameter since it was specific to the old deprecated model.

2. tests/integ/sagemaker/jumpstart/private_hub/model/test_jumpstart_private_hub_model.py

   • Replaced huggingface-txt2img-conflictx-complex-lineart with model-txt2img-stabilityai-stable-diffusion-v2-1-base in the TEST_MODEL_IDS set used for private hub model tests.

3. tests/integ/sagemaker/serve/test_schema_builder.py

   • Removed the HuggingFaceH4/zephyr-7b-alpha parametrized test case from test_model_builder_happy_path_with_task_provided_local_schema_mode. The JumpStart equivalent (huggingface-llm-huggingfaceh4-zephyr-7b-alpha) has been deprecated. The
     zephyr-7b-beta variant remains and covers the same test path (text-generation on ml.g5.2xlarge).

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[aviruthen]

Approved pending tests pass!