test: bootloader: move long-running test to nightly

Added nightly marker to test_direct_xip_upgrade_with_confirm
to reduce integration build time. One test from that suite
left in integration (reduces time from 10 to 5 minutes)

Signed-off-by: Grzegorz Chwierut <[email protected]>

Author: gchwier

tests/subsys/bootloader/upgrade/pytest/test_direct_xip.py

@@ -113,6 +113,7 @@ def factory_upgrade_test_direct_xip(
 class TestDirectXipWithRevert:
     """Test Direct XIP upgrade and revert scenarios."""
 
+    @pytest.mark.nightly
     def test_direct_xip_upgrade_with_confirm(
         self, dut: DeviceAdapter, shell: Shell, mcumgr: MCUmgr
     ):