Remove restrictions on having a save directory in /run/*

There are a lot of different scenarios in the wild where this is
interfering with using Warpinator at all, and considering how
permissions are set in /run, there's not much danger here.

Landlock is becoming and hopefully will be universally enabled
by default on distro kernels. Also the transfer symlink attack
potential is already low because of other checks that were
added in a4a0b0d.

src/util.py

@@ -371,13 +371,6 @@ def verify_save_folder():
         except ValueError:
             pass
 
-    # If you choose a read-only path to save to, it will create a hardlink to the real one in /run/user/...
-    # Consider this invalid to force the user to adjust their flatpak permissions to permit the normal path.
-    # One exception: Steamdeck mounts its media to /run/media (maybe others?)
-    path = str(save_path)
-    if path.startswith("/run") and not path.startswith("/run/media"):
-        return False
-
     return os.access(save_path, os.R_OK | os.W_OK)
 
 def home_is_writable():

src/warpinator.py

@@ -851,8 +851,6 @@ def manual_connect_to_host(self, host):
 
     def report_bad_save_folder(self):
         path = prefs.get_save_path()
-        if path.startswith("/run/user"):
-            path = os.path.basename(path)
         self.bad_save_folder_label.set_text(path)
         self.show_page("bad-save-folder")