Chore: Update ghcr.io/renovatebot/renovate Docker tag to v39.12.0

Author: grafanarenovatebot[bot]

.github/workflows/renovate-validate.yaml

@@ -13,5 +13,5 @@ jobs:
       - name: Validate renovate config
         run: |-
           # Renovate updates the line below. Please keep its formatting as it is.
-          export RENOVATE_IMAGE=ghcr.io/renovatebot/renovate:39.11.7@sha256:fb15bd3a3b295384a9785938c9785538f7f365dcec4690886a43e4648d3f31ed
+          export RENOVATE_IMAGE=ghcr.io/renovatebot/renovate:39.12.0@sha256:37991e23a3fa394e5b22cf448351c99efc69040c266da711055bd6146e962381
           docker run -i --rm -v $(realpath .):/repo -w /repo --entrypoint renovate-config-validator "$RENOVATE_IMAGE" --strict

.github/workflows/renovate.yaml

@@ -37,7 +37,7 @@ jobs:
       - name: Self-hosted Renovate
         uses: renovatebot/github-action@dd4d265eb8646cd04fc5f86ff8bc8d496d75a251 # v40.2.8
         with:
-          renovate-version: 39.11.7@sha256:fb15bd3a3b295384a9785938c9785538f7f365dcec4690886a43e4648d3f31ed
+          renovate-version: 39.12.0@sha256:37991e23a3fa394e5b22cf448351c99efc69040c266da711055bd6146e962381
           configurationFile: .github/renovate-app.json
           token: "${{ steps.app-token.outputs.token }}"
         env: