Revert pruning of old devices (#15360)

* Revert "Fix registering a device on an account with lots of devices (#15348)"

This reverts commit f0d8f66eaa.

* Revert "Delete stale non-e2e devices for users, take 3 (#15183)"

This reverts commit 78cdb72cd6.

tests/rest/client/test_register.py

@@ -794,53 +794,6 @@ class RegisterRestServletTestCase(unittest.HomeserverTestCase):
             ApprovalNoticeMedium.NONE, channel.json_body["approval_notice_medium"]
         )
 
-    def test_check_stale_devices_get_pruned(self) -> None:
-        """Check that if a user has some stale devices we log them out when they
-        log in a new device."""
-
-        # Register some devices, but not too many that we go over the threshold
-        # where we prune more aggressively.
-        user_id = self.register_user("user", "pass")
-        for _ in range(0, 50):
-            self.login(user_id, "pass")
-
-        store = self.hs.get_datastores().main
-
-        res = self.get_success(store.get_devices_by_user(user_id))
-        self.assertEqual(len(res), 50)
-
-        # Advance time so that the above devices are considered "old".
-        self.reactor.advance(30 * 24 * 60 * 60 * 1000)
-
-        self.login(user_id, "pass")
-
-        self.reactor.pump([60] * 10)  # Ensure background job runs
-
-        # We expect all old devices to have been logged out
-        res = self.get_success(store.get_devices_by_user(user_id))
-        self.assertEqual(len(res), 1)
-
-    def test_check_recent_devices_get_pruned(self) -> None:
-        """Check that if a user has many devices we log out the last oldest
-        ones.
-
-        Note: this is similar to above, except if we lots of devices we prune
-        devices even if they're not old.
-        """
-
-        # Register a lot of devices in a short amount of time
-        user_id = self.register_user("user", "pass")
-        for _ in range(0, 100):
-            self.login(user_id, "pass")
-            self.reactor.advance(100)
-
-        store = self.hs.get_datastores().main
-
-        # We keep up to 50 devices that have been used in the last week, plus
-        # the device that was last logged in.
-        res = self.get_success(store.get_devices_by_user(user_id))
-        self.assertEqual(len(res), 51)
-
 
 class AccountValidityTestCase(unittest.HomeserverTestCase):
     servlets = [