API: Integrate OpenAPI export script

Move OpenAPI export as an env var within the main function. This
allows for easy export by running main.

In addition, an env variable provides global and explicit state to
disable conditional wheel imports (ex. Exl2 and torch) which caused
errors at first.

Signed-off-by: kingbri <bdashore3@proton.me>

common/model.py

@@ -4,17 +4,20 @@ Manages the storage and utility of model containers.
 Containers exist as a common interface for backends.
 """
 
+import os
 import pathlib
 from loguru import logger
 from typing import Optional
 
-from backends.exllamav2.model import ExllamaV2Container
 from common import config
 from common.logger import get_loading_progress_bar
 from common.utils import unwrap
 
-# Global model container
-container: Optional[ExllamaV2Container] = None
+if not os.getenv("EXPORT_OPENAPI"):
+    from backends.exllamav2.model import ExllamaV2Container
+
+    # Global model container
+    container: Optional[ExllamaV2Container] = None
 
 
 def load_progress(module, modules):