Ensure we don't run updates more than once

[dkotter]

Description of the Change

As mentioned in #623, there's a scenario where manually triggering some of the Azure Image Processing Features from the attachment edit screen can result in an infinite loop.

As part of the refactoring done in #611, this was fixed so that we wouldn't ever encounter an infinite loop but we still end up running those update functions twice, which is not ideal.

This PR fixes that by ensuring we remove the hooked action before we update the attachment.

Closes #623

How to test the Change

1. Set up the Descriptive Text Generator Feature
2. Set it up to save the result to either Image caption or Image description (Alt text never had an issue)
3. On an image that has already been uploaded, go to the attachment edit screen
4. Check the box in the ClassifAI Image Processing metabox and save the attachment
5. Ensure the descriptive text is saved

Changelog Entry

Fixed - Ensure we only run image updates once.

Credits

Props @dkotter, @Sidsector9, @sksaju

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests pass.

[Sidsector9]

The code looks good but I'm seeing fatal errors for the following:

Regenerate smart thumbnail

Rescan for text

[dkotter]

The code looks good but I'm seeing fatal errors for the following:

Hmm.. do you have any specific steps you're taking here? I'm not able to reproduce the problem but in looking at the error message, it seems the image metadata is returning as a string instead of an array (which we use wp_get_attachment_metadata to get that and supposedly it always returns either an array or false).

I've added an additional check to ensure we don't proceed if the metadata isn't an array but would still be interested to know how you're able to reproduce this.

[Sidsector9]

Thanks for fixing this issue. Tests well 👍