[ota.esphome] Handle blank password the same as no password defined (#11271)

esphome/components/esphome/ota/__init__.py

@@ -19,6 +19,7 @@ from esphome.const import (
 from esphome.core import CORE, coroutine_with_priority
 from esphome.coroutine import CoroPriority
 import esphome.final_validate as fv
+from esphome.types import ConfigType
 
 _LOGGER = logging.getLogger(__name__)
 
@@ -136,11 +137,12 @@ FINAL_VALIDATE_SCHEMA = ota_esphome_final_validate
 
 
 @coroutine_with_priority(CoroPriority.OTA_UPDATES)
-async def to_code(config):
+async def to_code(config: ConfigType) -> None:
     var = cg.new_Pvariable(config[CONF_ID])
     cg.add(var.set_port(config[CONF_PORT]))
 
-    if CONF_PASSWORD in config:
+    # Password could be set to an empty string and we can assume that means no password
+    if config.get(CONF_PASSWORD):
         cg.add(var.set_auth_password(config[CONF_PASSWORD]))
         cg.add_define("USE_OTA_PASSWORD")
         # Only include hash algorithms when password is configured