[bk72xx_ble] Block BK7238 until the LibreTiny bonding partition fix lands (#18649)

tests/component_tests/bk72xx_ble/config/test_bk7238.yaml

@@ -0,0 +1,7 @@
+esphome:
+  name: bk-family-gate-7238
+
+bk72xx:
+  board: generic-bk7238
+
+bk72xx_ble:

tests/component_tests/bk72xx_ble/test_family_gate.py

@@ -16,6 +16,7 @@ from esphome.core import EsphomeError
         ("test_bk7231t.yaml", "BK7231T.*BLE 4.2"),
         ("test_bk7252.yaml", "BK7251.*BLE 4.2"),
         ("test_bk7231q.yaml", "BK7231Q.*no BLE"),
+        ("test_bk7238.yaml", "BK7238.*bootloader"),
     ],
 )
 def test_unsupported_family_rejected(