Built-in AI: Add /_chrome to .gitignore

The assets needed to run WPTs in
third_party/blink/web_tests/wpt_internal/ai/ are downloaded to the
_chrome folder. These should not be checked in to chromium.

Fixed: 390478068
Change-Id: I59d2f6d9f18599a8e84ca0ce49c5ef599fb0ea32
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6227747
Commit-Queue: Nathan Memmott <[email protected]>
Reviewed-by: Mike Wasserman <[email protected]>
Reviewed-by: Tsuyoshi Horo <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1415634}

Author: Nathan Memmott

.gitignore

@@ -88,6 +88,7 @@ vs-chromium-project.txt
 /MODULE.bazel
 /MODULE.bazel.lock
 
+/_chrome
 /_out
 /android_emulator_sdk
 /ash/ash_unittests_run.xml