extension: Fix manifest filename in error message (#22906)

This PR fixes the incorrect filename for the extension manifest being
used in an error message.

It should be `extension.toml` and not `extension.json`.

Release Notes:

- N/A
4aa4a40e2fMarshall Bowers committed on 1/9/2025, 5:38:46 PM· committed by GitHubparent5c239be
1 file changedLine totals unavailable