remove tricium config

Tricium today is not working for tint because it has not been migrated
to recipe-based. The removal also unblocks the lucicfg migration for
tint.

R=rharrison

Bug: chromium:1155210, tint:693
Change-Id: I5d85801ffaddde0c9cbd5f04af8ca580684a504d
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/47903
Kokoro: Kokoro <noreply+kokoro@google.com>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>

infra/config/global/tricium-prod.cfg

@@ -1,35 +0,0 @@
-selections {
-  function: "GitFileIsolator"
-  platform: UBUNTU
-}
-
-selections {
-  function: "Pylint"
-  platform: UBUNTU
-}
-
-selections {
-  function: "Spacey"
-  platform: UBUNTU
-}
-
-selections {
-  function: "SpellChecker"
-  platform: UBUNTU
-}
-
-selections {
-  function: "Cpplint"
-  platform: UBUNTU
-}
-
-repos {
-  gerrit_project {
-    host: "dawn-review.googlesource.com"
-    project: "tint"
-    git_url: "https://dawn.googlesource.com/tint"
-  }
-}
-
-service_account: "tricium-prod@appspot.gserviceaccount.com"
-swarming_service_account: "swarming@tricium-prod.iam.gserviceaccount.com"