Remove unused vrk_gov_root.pem test cert

Bug: 1266634
Change-Id: I3648ee9383b1b6c4a4dc35a0c4d61a7e67a37fb5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4412821


Commit-Queue: Hubert Chao <hchao@chromium.org>
Reviewed-by: Hubert Chao <hchao@chromium.org>
Auto-Submit: Matt Mueller <mattm@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1128701}