update gcp credentials (#384)

> `submit-queue` is red because every Cirrus job failed during the last post-submit run, presumably due to the thing this PR is fixing. Landing with that failing is the only possible way the land a tree fix.

I see. Manually merge to unblock the tree.
diff --git a/.cirrus.yml b/.cirrus.yml
index 6c908b2..18996d2 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -1,4 +1,4 @@
-gcp_credentials: ENCRYPTED[1816835da1e936dabb469b51501856ec8468676e35e967bd0fd720a815498e5ee6c8a6a79219ce273f67bcb8f1aa948a]
+gcp_credentials: ENCRYPTED[!0e63b52bd7e4fda1cd7b7bf2b4fe515a27fadbeaced01f5ad8b699b81d3611ed64c5d3271bcd8426dd914ef41cba48a0!]
 
 env:
   CHANNEL: "master" # Default to master when not explicitly set by a task.