fix(release): remove pull request header from release configuration

Author: JoachimLK

.github/release-please-config.json

@@ -10,7 +10,6 @@
       "include-component-in-tag": false,
       "include-v-in-tag": true,
       "pull-request-title-pattern": "chore: release v${version}",
-      "pull-request-header": ":rocket: Release v${version}",
       "changelog-sections": [
         { "type": "feat", "section": "✨ Features" },
         { "type": "fix", "section": "🐛 Bug Fixes" },