Silence JSON experiment warnings

Silence warning related to JSON import via `with`.
The feature is stable and in the spec.
Sadly we can't target this experiment warning only.

Bug: none
Change-Id: I1c2d3c74c6f0f6a3b573ba32c219616c3272de0c
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6197941
Commit-Queue: Benedikt Meurer <[email protected]>
Auto-Submit: Nikolay Vitkov <[email protected]>
Reviewed-by: Benedikt Meurer <[email protected]>

Author: Lightning00Blade

DEPS

@@ -309,7 +309,14 @@ hooks = [
     'name': 'VS Code settings',
     'pattern': '.',
     'condition': 'build_with_chromium == False',
-    'action': ['vpython3', 'third_party/node/node.py', '--output', 'scripts/deps/sync-vscode-settings.mjs']
+    'action': [
+      'vpython3',
+      'third_party/node/node.py',
+      '--output',
+      # Silence the "Importing JSON modules" warning
+      '--no-warnings=ExperimentalWarning',
+      'scripts/deps/sync-vscode-settings.mjs'
+    ]
   },
 ]