Various Plugins: Simplify return QStringList statements

Change-Id: Id014225851e6b9f8436387c681bea42e5de3b797
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/plugins/git/giteditor.cpp

@@ -292,7 +292,7 @@ QStringList GitEditorWidget::annotationPreviousVersions(const QString &revision)
     if (!gitClient().synchronousParentRevisions(
                 sourceWorkingDirectory(), revision, &revisions, &errorMessage)) {
         VcsOutputWindow::appendSilently(errorMessage);
-        return QStringList();
+        return {};
     }
     return revisions;
 }