[espnow] Fix string data generating invalid C++ char literals (#15493)

esphome/components/espnow/__init__.py

@@ -245,7 +245,7 @@ async def send_action(
 
     data = config.get(CONF_DATA, [])
     if isinstance(data, str):
-        data = [cg.RawExpression(f"'{c}'") for c in data]
+        data = list(data.encode())
     templ = await cg.templatable(data, args, byte_vector, byte_vector)
     cg.add(var.set_data(templ))
 

tests/components/espnow/common.yaml

@@ -29,6 +29,8 @@ espnow:
         data: !lambda 'return {0x01, 0x02, 0x03, 0x04, 0x05};'
     - espnow.broadcast:
         data: "Hello, World!"
+    - espnow.broadcast:
+        data: "it's a test"
     - espnow.broadcast:
         data: [0x01, 0x02, 0x03, 0x04, 0x05]
     - espnow.broadcast: