chore(deps): update grafana/writers-toolkit digest to 6537a9c

Signed-off-by: renovate-sh-app[bot] <219655108+renovate-sh-app[bot]@users.noreply.github.com>

Author: renovate-sh-app[bot]

.github/workflows/publish-technical-documentation-next.yml

@@ -17,6 +17,6 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       # publish-technical-documentation/v1.2.0
-      - uses: grafana/writers-toolkit/publish-technical-documentation@39cdc38767184996e25d611923f8ce697e33bc70
+      - uses: grafana/writers-toolkit/publish-technical-documentation@6537a9cb2a81fbb67947e4022497dd78c78c1791
         with:
           website_directory: content/docs/oncall/next