Roll gn from 6f8c0328ee29 to 197d7a5fa261

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/gn-dart-sdk
Please CC dart-engprod@google.com,dart-vm-gardener@rotations.google.com,dart-vm-team@google.com on the revert to ensure that a human
is aware of the problem.

To file a bug in gn: https://bugs.chromium.org/p/gn/issues/list
To file a bug in Dart SDK: https://github.com/dart-lang/sdk/issues

To report a problem with the AutoRoller itself, please file a bug:
https://issues.skia.org/issues/new?component=1389291&template=1850622

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

Cq-Include-Trybots: luci.dart.try:dart-sdk-linux-try;luci.dart.try:dart-sdk-linux-arm64-try;luci.dart.try:dart-sdk-mac-try;luci.dart.try:dart-sdk-mac-arm64-try;luci.dart.try:dart-sdk-win-try
Change-Id: Ib03f3c9b50ad247157d64c847b92c25fb20b2137
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/511540
Reviewed-by: Alexander Markov <alexmarkov@google.com>
Reviewed-by: Alexander Aprelev <aam@google.com>
Commit-Queue: Alexander Aprelev <aam@google.com>
Commit-Queue: dart-autoroll@skia-public.iam.gserviceaccount.com <dart-autoroll@skia-public.iam.gserviceaccount.com>

DEPS

@@ -83,7 +83,7 @@ vars = {
   "clang_version": "git_revision:deb6854eec93529b2bd30178d400ad2ee7665cd4",
 
   # https://chrome-infra-packages.appspot.com/p/gn/gn
-  "gn_version": "git_revision:6f8c0328ee29c76e3566a216f2f0cf2992daa6ed",
+  "gn_version": "git_revision:197d7a5fa261d011bb9db414031caeeb907ccfd1",
 
   "reclient_version": "re_client_version:28341fc74c68f05a5c8be35160ada940c4edb969",
   "download_reclient": True,