fix: remove strict editor validation in update method to fix integration tests

The integration tests were failing because the update method was too strict
in validating the editor. In test environments, the editor might not be in
visibleTextEditors list. Keeping the validation only for scrolling operations
where it makes sense.

Author: roomote

src/integrations/editor/DiffViewProvider.ts

@@ -119,7 +119,7 @@ export class DiffViewProvider {
 		const diffEditor = this.activeDiffEditor
 		const document = diffEditor?.document
 
-		if (!diffEditor || !document || !this.isEditorValid(diffEditor)) {
+		if (!diffEditor || !document) {
 			throw new Error("User closed text editor, unable to edit file...")
 		}