fix: Update prompt message content types to use Literal and add union type for content

[zalcit]

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Fixes #15858

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• This change requires a documentation update, included: Dify Document
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[Copilot]

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (2)

api/core/model_runtime/entities/message_entities.py:63

• [nitpick] The base class 'PromptMessageContent' is now empty after removing the original type field. Consider adding a brief comment explaining that this is intentional to support polymorphic behavior via the 'type' field defined in the subclasses.

pass

api/core/model_runtime/entities/message_entities.py:115

• [nitpick] Consider renaming 'PromptMessageContentUnionTypes' to 'PromptMessageContentUnion' for brevity and improved clarity.

PromptMessageContentUnionTypes = Annotated[

[crazywoola]

Hello, I rebased the code to the latest branch, could you fix the errors in the CI?

[zalcit]

Hello, I rebased the code to the latest branch, could you fix the errors in the CI?

@crazywoola done for this

[crazywoola]

Hello still have the same errors.

[zalcit]

Hello still have the same errors.

try again