Add document to allowed cacheable_types for anthropic

[marpulli]

Document is an allowed type as per the Anthropic docs:

Images & Documents: Content blocks in the messages.content array, in user turns

This example now works

import pathlib
from pydantic_ai import Agent, BinaryContent, CachePoint
from pydantic_ai.models.anthropic import AnthropicModel
from pydantic_ai.providers.anthropic import AnthropicProvider

model = AnthropicModel(
        "claude-3-5-haiku-20241022",
        provider=AnthropicProvider(api_key=SETTINGS.anthropic_api_key),
    )

    agent = Agent(model=model)
    binary_data = pathlib.Path("example.pdf").open("rb").read()

    user_prompt = [
        BinaryContent(
            data=binary_data,
            media_type="application/pdf",
        ),
        CachePoint(),
    ]

    result = await agent.run(
        user_prompt=user_prompt,
    )
    ```

[DouweM]

@marpulli Thanks Mark! Looks like the Cache control not supported for param type: error is now uncovered. Can you please either add a new test for a type that is still unsupported for cache control (assuming there is one you can easily create in Pydantic AI), or if not, add a # pragma: no cover comment to the line(s) in question?

[marpulli]

Thanks for a speedy review @DouweM! I've changed the test to use the thinking type as thinking blocks don't support caching with cache_control param according to the anthropic docs