Merge pull request matplotlib#23769 from matplotlib/dependabot/github_actions/mamba-org/provision-with-micromamba-13

Bump mamba-org/provision-with-micromamba from 12 to 13

Author: dopplershift

.github/workflows/nightlies.yml

@@ -49,7 +49,7 @@ jobs:
 
         # N.B. anaconda-client is only maintained on the main channel
       - name: Install anaconda-client
-        uses: mamba-org/provision-with-micromamba@v12
+        uses: mamba-org/provision-with-micromamba@v13
         with:
           environment-file: false
           environment-name: nightlies