Python: Fix azure api key check (#8912)

### Motivation and Context

Fix azure api key check

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### Description

Fix azure api key check

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### Contribution Checklist

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- [ ] The code builds clean without any errors or warnings
- [ ] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [ ] All unit tests pass, and I have added new tests where possible
- [ ] I didn't break anyone 😄

python/semantic_kernel/connectors/ai/open_ai/services/azure_chat_completion.py

@@ -94,15 +94,23 @@ def __init__(
         if not azure_openai_settings.chat_deployment_name:
             raise ServiceInitializationError("chat_deployment_name is required.")
 
-        # If the api_key is none, and the ad_token is none, and the ad_token_provider is none,
+        # If the async_client is None, the api_key is none, the ad_token is none, and the ad_token_provider is none,
         # then we will attempt to get the ad_token using the default endpoint specified in the Azure OpenAI settings.
-        if api_key is None and ad_token_provider is None and azure_openai_settings.token_endpoint and ad_token is None:
+        if (
+            async_client is None
+            and azure_openai_settings.api_key is None
+            and ad_token_provider is None
+            and ad_token is None
+            and azure_openai_settings.token_endpoint
+        ):
             ad_token = azure_openai_settings.get_azure_openai_auth_token(
                 token_endpoint=azure_openai_settings.token_endpoint
             )
 
-        if not azure_openai_settings.api_key and not ad_token and not ad_token_provider:
-            raise ServiceInitializationError("Please provide either api_key, ad_token or ad_token_provider")
+        if not async_client and not azure_openai_settings.api_key and not ad_token and not ad_token_provider:
+            raise ServiceInitializationError(
+                "Please provide either a custom client, or an api_key, an ad_token or an ad_token_provider"
+            )
 
         super().__init__(
             deployment_name=azure_openai_settings.chat_deployment_name,