tell team-canton-notifications on canton update failures (#18086)

ci/bash-lib.yml

@@ -46,7 +46,7 @@ steps:
       git -c user.name="Azure Pipelines Daml Build" \
           -c user.email="support@digitalasset.com" \
           commit \
-          -m "$(printf "$title\n\n$body\n\nCHANGELOG_BEGIN\nCHANGELOG_END\n")"
+          -m "$(printf "$title\n\n$body\n")"
       git push origin $branch:$branch
       jq -n --arg title "$title" \
             --arg branch "$branch" \

ci/cron/daily-compat.yml

@@ -277,7 +277,7 @@ jobs:
         else
             if [ "main" = "$(Build.SourceBranchName)" ]; then
                 git add build.sh test-common/canton/BUILD.bazel
-                open_pr "$branch" "update canton to $canton_tag/$canton2_version/$canton3_version"
+                open_pr "$branch" "update canton to $canton_tag/$canton2_version/$canton3_version" "tell-slack: canton"
                 az extension add --name azure-devops
                 trap "az devops logout" EXIT
                 echo "$(System.AccessToken)" | az devops login --org "https://dev.azure.com/digitalasset"

ci/prs.yml

@@ -115,8 +115,7 @@ jobs:
 
 - job: notify_user
   # No Slack tokens on forks
-  condition: and(eq(variables['Build.Reason'], 'PullRequest'),
-                 not(canceled()),
+  condition: and(not(canceled()),
                  eq(variables['System.PullRequest.IsFork'], 'False'))
   dependsOn:
     - git_sha
@@ -142,6 +141,10 @@ jobs:
             tell_slack "<@${user}> <https://dev.azure.com/digitalasset/daml/_build/results?buildId=$(Build.BuildId)|Build $(Build.BuildId)> for <https://github.com/digital-asset/daml/pull/$(pr.num)|PR $(pr.num)> has completed with status $(build_status)." \
                        "$(Slack.team-daml-ci)"
         fi
+        if [ "$(git log -n1 --format="%(trailers:key=tell-slack,valueonly)" HEAD)" = "canton" ]; then
+            tell_slack "<https://dev.azure.com/digitalasset/daml/_build/results?buildId=$(Build.BuildId)|Build $(Build.BuildId)> for <https://github.com/digital-asset/daml/pull/$(pr.num)|canton update PR $(pr.num)> has completed with status $(build_status)." \
+                       "$(Slack.team-canton-notifications)"
+        fi
 
 - job: self_service_compat_test
   pool: