Fixed a bug in kiwix-desktop's source publishing step

The bug was there since 2018. It's strange that it didn't cause problems
with previous releases. The most plausible explanation is that this is
the first time when the sources of kiwix-desktop are being published
via this procedure.

kiwixbuild/dependencies/base.py

@@ -524,8 +524,8 @@ class QMakeBuilder(MakeBuilder):
             *neutralEnv("git_command"),
             "archive",
             "-o",
-            f"{self.build_path}/{self.target_full_name()}.tar.gz",
-            f"--prefix={self.target_full_name()}/",
+            f"{self.build_path}/{self.target.full_name()}.tar.gz",
+            f"--prefix={self.target.full_name()}/",
             "HEAD",
         ]
         run_command(command, self.source_path, context)