🍞 fix: don't show 'deleting file' toast on attached files (#13239)

There are two ways to add a file to a conversation:

1. Uploading a new file.
2. Using an existing file (from the side panel).

If you decide to remove the file, the behavior differs depending on
how it was added. If you just uploaded a new file, it gets deleted
from the conversation & the system. But if it's an existing file,
then it only gets removed from the conversation (but not deleted).

However, in both cases, it would show a toast saying that the file
was deleted, which is incorrect for the "existing file" case.

Now we check whether the file is `attached` (to the system) before
showing the deletion toast, and skip showing it if we're not actually
deleting the file.

client/src/components/Chat/Input/Files/FileRow.tsx

@@ -115,7 +115,7 @@ export default function FileRow({
               if (abortUpload && file.progress < 1) {
                 abortUpload();
               }
-              if (file.progress >= 1) {
+              if (file.progress >= 1 && !file.attached) {
                 showToast({
                   message: localize('com_ui_deleting_file'),
                   status: 'info',