Add release.yaml (#459)

This adds a `release.yml` file to remove dependabot / renovate PRs from
auto-generated release notes.

---------

Co-authored-by: Stefan VanBuren <svanburen@buf.build>

Author: AdrienVannson

.github/release.yaml

@@ -0,0 +1,6 @@
+changelog:
+  exclude:
+    labels:
+      - ignore-for-release
+    authors:
+      - renovate[bot]