This PR updates the extension list to disable remote entries when the
corresponding dev extension is installed.

Here is what this looks like:

<img width="1189" alt="Screenshot 2024-04-15 at 4 09 45 PM"
src="https://github.com/zed-industries/zed/assets/1486634/48bb61d4-bc85-4ca6-b233-716831dfa7d8">


Release Notes:

- Disabled extension entries when there is a development copy of that
extension installed.