Featured image button opens a dialog but misses an aria-haspopup attribute

[afercia]

Description

In the Post Summary pael, the Set featured image button does open a dialog. However, it misses an aria-haspopup="dialog" attribute to inform screen reader users it will open a dialog.
Same applies to the 'Replace' button.

Screenshot with Safari and VoiceOver announcing the button. No information is provided about the dialog.

Step-by-step reproduction instructions

• Use a screen reader.
• Navigate to the Set featured image button.
• Observe the button is announced without any meaningful information that is will open a dialog.
• Set an image.
• Repeat the test for the 'Replace' button.

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

Yes