[pgp] Fix ruff errors

pgp/backend/python_gnupg.py

@@ -73,7 +73,7 @@ class PGP(metaclass=Singleton):
         result = self._pgp.decrypt(data.encode("utf8"))
         return str(result)
 
-    @lru_cache(maxsize=8)
+    @lru_cache(maxsize=8)  # noqa: B019
     def sign(self, payload: str | None, key_id: str) -> str:
         if payload is None:
             payload = ""

pgp/gtk/key.py

@@ -158,7 +158,7 @@ class ChooseGPGKeyDialog(GajimAppWindow):
         model = cast(Gtk.ListStore, self._ui.keys_treeview.get_model())
         model.set_sort_func(1, self._sort)
 
-        for key_id in secret_keys.keys():
+        for key_id in secret_keys:
             model.append((key_id, secret_keys[key_id]))
 
         self.set_child(self._ui.box)

pgp/modules/events.py

@@ -15,8 +15,8 @@
 from __future__ import annotations
 
 from typing import Any
-from typing import Callable
 
+from collections.abc import Callable
 from dataclasses import dataclass
 from dataclasses import field
 

pgp/modules/util.py

@@ -39,7 +39,7 @@ def find_gpg():
             gpg_cmd = binary + " -h >nul 2>&1"
         else:
             gpg_cmd = binary + " -h >/dev/null 2>&1"
-        if subprocess.call(gpg_cmd, shell=True):
+        if subprocess.call(gpg_cmd, shell=True):  # noqa: S602
             return False
         return True