.github: don't ignore dependabot on releases (hashicorp#199)

The PRs merged by dependabot may affect the stability of releases and
should be included in the changelog.

In the past they hadn't been included as they may induce too much
noise, we re-enable them with this commit, and will rollback if
necessary.

.github/release.yml

@@ -2,8 +2,6 @@ changelog:
   exclude:
     labels:
       - ignore-for-release
-    authors:
-      - dependabot
   categories:
     - title: Breaking Changes 🛠
       labels: