Bump azure/setup-helm from 1 to 3 (grafana#7608)

Bumps [azure/setup-helm](https://github.com/azure/setup-helm) from 1 to
3.

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/helm-ci.yml

@@ -45,7 +45,7 @@ jobs:
           fetch-depth: 0
 
       - name: Set up Helm
-        uses: azure/setup-helm@v1
+        uses: azure/setup-helm@v3
         with:
           version: v3.8.2