"popup-backdrop-filter.js" missing errors in web browsers

I used to use the popup-backdrop-filter a while back. I heard that Home Assistant already added this feature builtin; and, no longer needed to be added/installed manually for HACS. So, I commented out the explicit reference to it in ui-lovelace.yaml file and also removed the reference to its github URL under HACS custom repositories.

resources:
  # - url: /hacsfiles/popup-backdrop-filter/popup-backdrop-filter.js
  #   type: module

However, even after I commented it out and restarted Home Assistant, I’m getting web browser 404 error complaining that the resource is not there anymore:

How do I remove it completely from Home Assistant? So I don’t get these errors? I already cleared my web browser cache. Is there a specific cache file in Home Assistant I need to delete too?

NOTE: The only way to prevent these errors is to put the /hacsfiles/popup-backdrop-filter/popup-backdrop-filter.js file back… even while it’s clearly commented out in the ui-lovelace.yaml file; …which suggests it’s stuck somewhere in cache?

NOTE: I do take advantage of blur background in my theme (see below). However, there are definitely no references to the actual module file anywhere on Home Assistant that I know of.
theme.yaml

  # Blur background for popups
  dialog-backdrop-filter: blur(12px)
  iron-overlay-backdrop-opacity: 0
  iron-overlay-backdrop-background-color: rgba(0, 0, 0, 0.32)

Anyway, I’m hoping there’s a simple way to remove it completely/correctly from my setup.