Update Mergify config to check GitHub Actions

This updates the Mergify config so that it checks
the GitHub Actions. We also remove the backport
labels for the branches that we recently renamed
as EOL.

.mergify.yml

@@ -8,7 +8,30 @@ pull_request_rules:
     conditions:
     - label!=work-in-progress
     - '#approved-reviews-by>=1'
-    - status-success=Travis CI - Pull Request
+    - status-success=doc (docs)
+    - status-success=doc (docs-gnocchi-web)
+
+    - status-success=check (pep8)
+
+    - status-success=test (py36-postgresql-file-upgrade-from-4.3)
+    - status-success=test (py36-mysql-file)
+    - status-success=test (py36-mysql-swift)
+    - status-success=test (py36-mysql-s3)
+    - status-success=test (py36-postgresql-file)
+    - status-success=test (py36-postgresql-swift)
+    - status-success=test (py36-postgresql-s3)
+
+    - status-success=test (py38-mysql-ceph-upgrade-from-4.3)
+    - status-success=test (py38-postgresql-file-upgrade-from-4.3)
+    - status-success=test (py38-mysql-file)
+    - status-success=test (py38-mysql-swift)
+    - status-success=test (py38-mysql-s3)
+    - status-success=test (py38-mysql-ceph)
+    - status-success=test (py38-postgresql-file)
+    - status-success=test (py38-postgresql-swift)
+    - status-success=test (py38-postgresql-s3)
+    - status-success=test (py38-postgresql-ceph)
+
   - name: automatic merge backports from Mergify
     actions:
       merge:
@@ -20,6 +43,7 @@ pull_request_rules:
     - label!=work-in-progress
     - author=mergify[bot]
     - status-success=Travis CI - Pull Request
+
   - name: dismiss reviews on additional commit
     actions:
       dismiss_reviews: {}
@@ -29,42 +53,14 @@ pull_request_rules:
   - actions:
       backport:
         branches:
-        - stable/3.0
-    conditions:
-    - label=backport-to-3.0
-    name: backport stable/3.0
-  - actions:
-      backport:
-        branches:
-        - stable/3.1
-    conditions:
-    - label=backport-to-3.1
-    name: backport stable/3.1
-  - actions:
-      backport:
-        branches:
-        - stable/4.0
-    conditions:
-    - label=backport-to-4.0
-    name: backport stable/4.0
-  - actions:
-      backport:
-        branches:
-        - stable/4.1
-    conditions:
-    - label=backport-to-4.1
-    name: backport stable/4.1
-  - actions:
-      backport:
-        branches:
-        - stable/4.2
+        - stable/4.3
     conditions:
-    - label=backport-to-4.2
-    name: backport stable/4.2
+    - label=backport-to-4.3
+    name: backport stable/4.3
   - actions:
       backport:
         branches:
-        - stable/4.3
+        - stable/4.4
     conditions:
-    - label=backport-to-4.3
-    name: backport stable/4.3
+    - label=backport-to-4.4
+    name: backport stable/4.4