Revert "Update V8 to version 7.8.283."

This reverts commit ae084e61.

Reason for revert: chromium build failure https://ci.chromium.org/p/chromium/builders/ci/linux-archive-dbg/3414

Original change's description:
> Update V8 to version 7.8.283.
>
> Summary of changes available at:
> https://chromium.googlesource.com/v8/v8/+log/681aa450..9ddd0c4c
>
> Please follow these instructions for assigning/CC'ing issues:
> https://v8.dev/docs/triage-issues
>
> Please close rolling in case of a roll revert:
> https://v8-roll.appspot.com/
> This only works with a Google account.
>
> CQ_INCLUDE_TRYBOTS=luci.chromium.try:linux-blink-rel
> CQ_INCLUDE_TRYBOTS=luci.chromium.try:linux_optional_gpu_tests_rel
> CQ_INCLUDE_TRYBOTS=luci.chromium.try:mac_optional_gpu_tests_rel
> CQ_INCLUDE_TRYBOTS=luci.chromium.try:win_optional_gpu_tests_rel
> CQ_INCLUDE_TRYBOTS=luci.chromium.try:android_optional_gpu_tests_rel
>
> TBR=hablich@chromium.org,v8-waterfall-sheriff@grotations.appspotmail.com
>
> Change-Id: I5efb235167c182e0425b29399372f0f14883e2b1
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1786898
> Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
> Commit-Queue: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
> Cr-Commit-Position: refs/heads/master@{#693524}

TBR=hablich@chromium.org,v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com,v8-waterfall-sheriff@grotations.appspotmail.com

CQ_INCLUDE_TRYBOTS=luci.chromium.try:linux-blink-rel
CQ_INCLUDE_TRYBOTS=luci.chromium.try:linux_optional_gpu_tests_rel
CQ_INCLUDE_TRYBOTS=luci.chromium.try:mac_optional_gpu_tests_rel
CQ_INCLUDE_TRYBOTS=luci.chromium.try:win_optional_gpu_tests_rel
CQ_INCLUDE_TRYBOTS=luci.chromium.try:android_optional_gpu_tests_rel

Change-Id: I71e75ae25f1f4d03b60b843a45f17bec2c151ef3
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1787597
Commit-Queue: Henrik Boström <hbos@chromium.org>
Reviewed-by: Olga Sharonova <olka@chromium.org>
Cr-Commit-Position: refs/heads/master@{#693598}

DEPS

@@ -166,7 +166,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.
-  'v8_revision': '9ddd0c4c1893034fb78a159143eb61fa761f33de',
+  'v8_revision': '681aa45056dac848ba6c38896f6b543dd58e1353',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling swarming_client
   # and whatever else without interference from each other.