Merge pull request #2971 from cta-observatory/dependabot/github_actions/mamba-org/setup-micromamba-3

Bump mamba-org/setup-micromamba from 2 to 3

Author: maxnoe

.github/workflows/ci.yml

@@ -123,7 +123,7 @@ jobs:
 
       - name: mamba setup
         if: matrix.install-method == 'mamba' && contains(github.event.pull_request.labels.*.name, 'documentation-only') == false
-        uses: mamba-org/setup-micromamba@v2
+        uses: mamba-org/setup-micromamba@v3
         with:
           environment-file: environment.yml
           cache-downloads: true