Allow users to add hreflang attribute for Internationalization

### Feature Description

AMP currently does not support the `hreflang` attribute on `` tags with the attribute. This allows users to add internationalization to AMP pages to effectively and target specific language or regional audiences.

I will suggest adding a filter which will allow programs and users to customize the attribute as per thier requirements.

ref: https://amp.dev/documentation/examples/websites/guides/internationalization/

### Acceptance Criteria

_No response_

### Implementation Brief

_No response_

### QA Testing Instructions

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### Demo

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### Changelog Entry

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No implementation file, test, or entry point is named. Start by tracing how AMP link-tag attributes are filtered or sanitized, then review the linked internationalization guidance. Done means users can configure hreflang on supported link tags without weakening AMP validation, with tests covering the behavior.

Written by the indexing model from the issue text.