VcsCommand: Get rid of abort()

Use destructor of VcsCommand instead.

Change-Id: Ie914d016c6d3d57a88674ce8534d5edec4bc79c1
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/vcsbase/vcscommand.h

@@ -105,7 +105,6 @@ public:
                 const Utils::FilePath &workingDirectory = {},
                 const Utils::ExitCodeInterpreter &interpreter = {});
     void execute(); // Execute tasks asynchronously!
-    void abort();
 
     void addFlags(unsigned f);