scripts/uninstall_module: import signal module

With Python 3.13, the `subprocess` module now uses the
`posix_spawn()` function [1], which requires the `signal`
module to be imported.

Fixes: checkpoint-restore#2607

[1] https://docs.python.org/3/whatsnew/3.13.html#subprocess

Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>

scripts/uninstall_module.py

@@ -10,6 +10,11 @@
 import subprocess
 import sys
 
+# With Python 3.13 the subprocess module uses `posix_spawn()` function
+# which requires loading the `signal`:
+#     https://docs.python.org/3/whatsnew/3.13.html#subprocess
+import signal
+
 import importlib_metadata