[Issue] Allow usage of cacheTags for FPC

[m2-assistant]

This issue is automatically created based on existing pull request: #31310: Allow usage of cacheTags for FPC

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Regarding the AbstarctBlock implementation of getCacheTags, tags from identities are merges to cache tags anyway, so we could use it safely.
Also Magento does not recommend to implement new Blocks, so we could declare the block's tags in the layout xml for the FPC.

Description (*)

Related Pull Requests

Fixed Issues (if relevant)

1. Fixes magento/magento2#<issue_number>

Manual testing scenarios (*)

1. ...
2. ...

Questions or comments

Contribution checklist (*)

• Pull request has a meaningful description of its purpose
• All commits are accompanied by meaningful commit messages
• All new or changed code is covered with unit/integration tests (if applicable)
• All automated tests passed successfully (all builds are green)

[m2-assistant]

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[engcom-Hotel]

Hello @thomas-kl1,

Thanks for the report and collaboration!

We have reviewed all the comments and changes in the related PR. However, we are still unsure how to reproduce this issue.

Could you please provide us with the steps to reproduce the issue?

Thank you!

[thomas-kl1]

Hello, it's not an issue, it's a request for improvement so we can use cache_tags data available on block within the FPC without having to create a new concrete block which implements IdentityInterface.

[engcom-Hotel]

Thanks @thomas-kl1, for the reply!

We are moving this issue as a feature request.