fix: use activity context for Toast

Fixes a newly introduced warning in API 33

> Tried to access visual service WindowManager from a non-visual Context:app.passwordstore.Application@d2801f8 WindowManager
> should be accessed from Activity or other visual Context. Use an Activity or a Context created with
> Context#createWindowContext(int, Bundle), which are adjusted to the configuration and visual bounds of an area on screen.

app/src/main/java/app/passwordstore/util/git/GitCommandExecutor.kt

@@ -103,7 +103,7 @@ class GitCommandExecutor(
                     RemoteRefUpdate.Status.UP_TO_DATE -> {
                       withContext(Dispatchers.Main) {
                         Toast.makeText(
-                            activity.applicationContext,
+                            activity,
                             activity.applicationContext.getString(R.string.git_push_up_to_date),
                             Toast.LENGTH_SHORT
                           )