[cleanup] Remove deprecated build flag v8_enable_raw_heap_snapshots

It has been deprecated for a couple of years and there is no evidence of
anybody still using it.

Change-Id: I454f2f718aa50c295b29faf62cd0313a5e6e97d7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3417495Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#79177}

BUILD.gn

@@ -837,10 +837,6 @@ config("features") {
   defines +=
       [ "V8_TYPED_ARRAY_MAX_SIZE_IN_HEAP=${v8_typed_array_max_size_in_heap}" ]
 
-  assert(
-      !v8_enable_raw_heap_snapshots,
-      "This flag is deprecated and is now available through the inspector interface as an argument to profiler's method `takeHeapSnapshot`. Consider using blink's flag `enable_additional_blink_object_names` to get better naming of internal objects.")
-
   if (v8_enable_future) {
     defines += [ "V8_ENABLE_FUTURE" ]
   }

gni/v8.gni

@@ -32,10 +32,6 @@ declare_args() {
   # Support for backtrace_symbols on linux.
   v8_enable_backtrace = ""
 
-  # This flag is deprecated and is now available through the inspector interface
-  # as an argument to profiler's method `takeHeapSnapshot`.
-  v8_enable_raw_heap_snapshots = false
-
   # Use external files for startup data blobs:
   # the JS builtins sources and the start snapshot.
   v8_use_external_startup_data = ""