Adding VS code workspace files to .gitignore

Change-Id: I65a0590b3d745b0a209ae8c7a7fc634e50ac4f54
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2518728Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Commit-Queue: Filip Gorski <fgorski@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823999}

.gitignore

 /client-py/
 *.bak
+*.code-workspace
 *.mk
 *.ncb
 *.opensdf