End MacOS arm64 / Linux Docker incident. (#2710)

Fixes https://github.com/bazelbuild/continuous-integration/issues/2700

buildkite/emergency.yml

diff --git a/buildkite/emergency.yml b/buildkite/emergency.yml
index 7a4015c..3207eea 100644
--- a/buildkite/emergency.yml
+++ b/buildkite/emergency.yml
@@ -17,6 +17,6 @@
 # Please do not clear or delete this file when an incident is over.
 # Instead, simply replace all values with empty strings ("").
 ---
-message: "Jobs on RBE Ubuntu & MacOS arm64 are failing due to an ongoing outage."
-issue_url: "https://github.com/bazelbuild/continuous-integration/issues/2700"
+message: ""
+issue_url: ""
 last_good_bazel: ""