[build] increase timeout for signing (#1285)

Signing *appears* to be working, but times out at about 2 hours.

We increased this to 120 minutes in 7087b1e.

Let's increase the timeout further to 180 minutes to see if that helps.

Author: jonathanpeppers

build/ci/stage-sign-artifacts.yml

@@ -10,7 +10,7 @@ stages:
 
   - template: sign-artifacts/jobs/v4.yml@yaml-templates
     parameters:
-      timeoutInMinutes: 120
+      timeoutInMinutes: 180
       artifactName: output-windows
       usePipelineArtifactTasks: true
       checkoutType: self