Update github actions

The usage of GRAFANA_API_KEY environment variable is deprecated and it
should be changed to GRAFANA_ACCESS_POLICY_TOKEN

Author: lpetrora

.github/workflows/ci.yml

@@ -78,7 +78,7 @@ jobs:
         id: build-signed
         uses: ./.github/build/
         env:
-          GRAFANA_API_KEY: ${{ secrets.GRAFANA_API_KEY }}
+          GRAFANA_ACCESS_POLICY_TOKEN: ${{ secrets.GRAFANA_API_KEY }}
         with:
           release: false
           signed: true

.github/workflows/release.yml

@@ -20,7 +20,7 @@ jobs:
         id: build-signed
         uses: ./.github/build/
         env:
-          GRAFANA_API_KEY: ${{ secrets.GRAFANA_API_KEY }}
+          GRAFANA_ACCESS_POLICY_TOKEN: ${{ secrets.GRAFANA_API_KEY }}
         with:
           release: true
           signed: true