docs: remove mention of TypeAdapter in vendored-schema-1-implementation.md

Pydantic models can generate their own JSONSchema,
and we do generate the JSONSchema directly from the
models. TypeAdapter in Pydantic has other uses,
but we are not using it here.

Author: candleindark

doc/design/vendored-schema-1-implementation.md

@@ -18,7 +18,6 @@ The implemented solution addresses these issues by:
 
 1. Creating an API endpoint to dynamically generate JSONSchema from the Pydantic models at runtime
 2. Updating the info endpoint to point to our local schema endpoint instead of GitHub
-3. Implementing proper serialization using Pydantic's TypeAdapter to generate the JSONSchema
 
 ### New Endpoints
 
@@ -27,8 +26,6 @@ We've added the following API endpoints:
 - `/api/schemas/available/` - Returns the list of available schema models that can be used as a query parameter value for the `/api/schemas/` endpoint
 - `/api/schemas/` - Returns the JSONSchema for a queried model specified with the `model` query parameter (e.g., `?model=Dandiset`)
 
-These endpoints use Pydantic's TypeAdapter to generate the JSONSchema directly from the models, ensuring that any runtime vendorization or customization is reflected in the schema.
-
 ### Updated Info Endpoint
 
 The `/api/info/` endpoint has been updated to point to our local schema endpoint instead of the GitHub URL. This ensures that frontend clients like the web UI use the schema that matches the running backend exactly, including any vendorization.