fix: skip parent update from deleted tags

[rpenido]

Description

This PR prevents creating an UpdateParent action associated with a Tag that will be deleted.

Example:

- Tag 1
  - Tag 1.1
    - Tag 1.1.1

Actions before PR:

#1 Delete Tag 1
#2 Delete Tag 1.1
#3 Delete Tag 1.1.1
#4 Update parent tag of Tag 1.1 from Tag 1 to None (** THIS FAILS BECAUSE Tag 1.1 WAS DELETED **)
#5 Update parent tag of Tag 1.1.1 from Tag 1.1 to None  (** THIS FAILS BECAUSE Tag 1.1.1 WAS DELETED **)

Actions after PR:

#1 Delete Tag 1
#2 Delete Tag 1.1
#3 Delete Tag 1.1.1

It also checks if the Tag actually exists in the database before executing the Delete action. In the example above, because we didn't update the parent of tags 1.1 and 1.1.1, actions #2 and #3 should be skipped because both tags were cascade deleted on action #1.

Testing instructions

• Please ensure that the tests cover the expected behavior and that the new test that reproduces the bug passes

---

Private-ref:

• FAL-3568

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[bradenmacdonald]

Merging now. I see there's no version bump - let me know if we need to add one at some point, or just wait to combine this with other changes.

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