Remove old definition of the macro RTC_NOTREACHED

Bug: webrtc:9065
Change-Id: I3cb166f217893808af5708ede69abaebb5bde28e
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/237809
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35356}
diff --git a/rtc_base/checks.h b/rtc_base/checks.h
index 028de45..863e39d 100644
--- a/rtc_base/checks.h
+++ b/rtc_base/checks.h
@@ -445,8 +445,6 @@
 
 #define RTC_UNREACHABLE_CODE_HIT false
 #define RTC_DCHECK_NOTREACHED() RTC_DCHECK(RTC_UNREACHABLE_CODE_HIT)
-// Deprecated. Use RTC_DCHECK_NOTREACHED instead
-#define RTC_NOTREACHED() RTC_DCHECK(RTC_UNREACHABLE_CODE_HIT)
 
 // Kills the process with an error message. Never returns. Use when you wish to
 // assert that a point in the code is never reached.