chore(ci): Mergify - merge Autobumps on release-* (#2034) (#2037)

And request review for failed autobump builds on master and release branches.

Lastly, remove Travis CI related rule. It's not used.

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
(cherry picked from commit 04f77fb)

Co-authored-by: kskewes-sf <[email protected]>

.mergify.yml

@@ -23,20 +23,6 @@ pull_request_rules:
         strict: smart
       label:
         add: ["auto merged"]
-  # This rule exists to handle release branches that are still building using Travis CI instead of
-  # using Github actions. It can be deleted once all active release branches are running Github actions.
-  - name: Automatically merge release branch changes on Travis CI success and release manager review
-    conditions:
-      - base~=^release-
-      - status-success=continuous-integration/travis-ci/pr
-      - "label=ready to merge"
-      - "approved-reviews-by=@release-managers"
-    actions:
-      merge:
-        method: squash
-        strict: smart
-      label:
-        add: ["auto merged"]
   - name: Automatically merge PRs from maintainers on CI success and review
     conditions:
       - base=master
@@ -51,7 +37,7 @@ pull_request_rules:
         add: ["auto merged"]
   - name: Automatically merge autobump PRs on CI success
     conditions:
-      - base=master
+      - base~=^(master|release-)
       - status-success=build
       - "label~=autobump-*"
       - "author:spinnakerbot"
@@ -63,7 +49,7 @@ pull_request_rules:
         add: ["auto merged"]
   - name: Request reviews for autobump PRs on CI failure
     conditions:
-      - base=master
+      - base~=^(master|release-)
       - status-failure=build
       - "label~=autobump-*"
       - base=master