Remove include from runtime_enabled_features template

BUG=242216

Change-Id: I6f897509727b026b9d1f17227b0621b30821cc56
Reviewed-on: https://chromium-review.googlesource.com/c/1286937
Commit-Queue: David Bokan <bokan@chromium.org>
Reviewed-by: David Bokan <bokan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600754}

third_party/blink/renderer/build/scripts/templates/runtime_enabled_features.h.tmpl

@@ -10,7 +10,6 @@
 
 #include "third_party/blink/renderer/platform/platform_export.h"
 #include "third_party/blink/renderer/platform/wtf/allocator.h"
-#include "third_party/blink/renderer/platform/wtf/forward.h"
 
 namespace blink {