[filegraph] Skip git test
[filegraph] Skip git test

THe git test fails with unclear reason
https://logs.chromium.org/logs/infra/buildbucket/cr-buildbucket.appspot.com/8864634177878601952/+/u/go_test/stdout
Skip it for now.

TBR=tandrii@chromium.org
NOTREECHECKS=true
Change-Id: Ib5f313e810f2b2f1dd5d95621ecdd54d91454185
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2517545
Reviewed-by: Nodir Turakulov <ef4933a197ef7b4b3f55f1bec4942aead3637a2a@chromium.org>
Commit-Queue: Nodir Turakulov <ef4933a197ef7b4b3f55f1bec4942aead3637a2a@chromium.org>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go