[diagnostics] Disable system instrumentation by default

Disabling temporarily since it breaks chrome cross-builds on linux.

Bug: v8:11043, chromium:1196278
Change-Id: I2d2a0c8b88b357da52217d1672aaa1377759df07
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2805816
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73809}

BUILD.gn

@@ -41,7 +41,7 @@ declare_args() {
   v8_enable_future = false
 
   # Sets -DSYSTEM_INSTRUMENTATION. Enables OS-dependent event tracing
-  v8_enable_system_instrumentation = true
+  v8_enable_system_instrumentation = false
 
   # Sets the GUID for the ETW provider
   v8_etw_guid = ""