[esp8266] NOLINT redundant-declaration on system_soft_wdt_feed forward decl

clang-tidy flagged the forward decl in hal_esp8266.h because <user_interface.h>
also declares the function (when included via SDK headers). Both decls are
identical `extern "C"` so the redundancy is harmless; suppress the warning
on the hal_esp8266.h side.

esphome/core/hal/hal_esp8266.h

@@ -21,6 +21,7 @@ extern "C" unsigned long millis(void);
 // NOLINTEND(google-runtime-int,readability-identifier-naming,readability-redundant-declaration)
 
 // Forward decl from <user_interface.h> for arch_feed_wdt() inline below.
+// NOLINTNEXTLINE(readability-redundant-declaration)
 extern "C" void system_soft_wdt_feed(void);
 
 namespace esphome {