Unable to remove keywords

[laijasmine]

Describe the bug In any dataset you can only add new keywords using the webform but the removal of keywords is buggy

To Reproduce Steps to reproduce the behavior:

1. Go to any dataset
2. Edit the keywords in the metadata using the webform
3. View the saved metadata

• If the first keyword in the list is removed, all the other keywords of the same keyword set will be removed with it. eg. all the keywords belonging to the GCMD keywords will be removed if the first keyword in the GCMD keywords is removed. All other keywords with the Keyword Thesaurus set as none will be untouched.
• If any other keyword is removed there will be no change in the keywords and the list will remain the same.

Expected behavior Users should be able to remove any keywords using the web editor and have it save.

Additional context Issue raised in this RT ticket: https://support.nceas.ucsb.edu/rt/Ticket/Display.html?id=21611

[vchendrix]

@robyngit here is a screen capture of the issue above.

https://github.com/user-attachments/assets/4832eb30-cbeb-45e6-9ae7-2b57c6af2c8d

[robyngit]

That's helpful thank you @vchendrix !