[noise] Initialize reserved field for gcc 15

gcc 15 extends -Wmissing-field-initializers to designated
initializers; NoiseProtocolId's reserved array was omitted.

esphome/components/noise/noise_handshake.cpp

@@ -37,6 +37,7 @@ int NoiseResponderHandshake::init(const psk_t &psk, const uint8_t *prologue, siz
       .cipher_id = NOISE_CIPHER_CHACHAPOLY,
       .hash_id = NOISE_HASH_SHA256,
       .hybrid_id = NOISE_DH_NONE,
+      .reserved = {},
   };
 
   int err = noise_handshakestate_new_by_id(&this->handshake_, &nid, NOISE_ROLE_RESPONDER);