Python: Fix pydantic alias issue (#10027)

### Motivation and Context
fix #10026

### Description

This PR removes the alias as pydantic requires the usage of the alias
when initializing the class not the original name which prevents this
code from working.

```py
cosmosdb_settings = AzureCosmosDBSettings.create(
                env_file_path=env_file_path,
                connection_string=cosmos_connstr,
            )
```

### Contribution Checklist

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- [x] The code builds clean without any errors or warnings
- [x] 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
- [x] All unit tests pass, and I have added new tests where possible
- [x] I didn't break anyone 😄

python/semantic_kernel/connectors/memory/azure_cosmosdb/azure_cosmosdb_settings.py

@@ -2,7 +2,7 @@
 
 from typing import ClassVar
 
-from pydantic import Field, SecretStr
+from pydantic import ConfigDict, Field, SecretStr
 
 from semantic_kernel.kernel_pydantic import KernelBaseSettings
 from semantic_kernel.utils.experimental_decorator import experimental_class
@@ -22,3 +22,7 @@ class AzureCosmosDBSettings(KernelBaseSettings):
 
     api: str | None = None
     connection_string: SecretStr | None = Field(None, alias="AZCOSMOS_CONNSTR")
+
+    model_config = ConfigDict(
+        populate_by_name=True,
+    )