Remove release notes template in favor of global one (#1957)

.github/release.yml

@@ -1,21 +0,0 @@
-changelog:
-  exclude:
-    authors:
-      - knative-automation
-  categories:
-    - title: 🚨 Breaking or Notable Changes
-      labels:
-        - kind/api-change
-        - kind/deprecation
-        - kind/removal
-        - kind/security
-    - title: 💫 New Features & Enhancements
-      labels:
-        - kind/feature
-        - kind/enhancement
-    - title: 🐞 Bug Fixes
-      labels:
-        - kind/bug
-    - title: Other Changes
-      labels:
-        - "*"