Update mamba-org/setup-micromamba to v2.

Author: hameerabbasi

.github/workflows/ci.yml

@@ -34,7 +34,7 @@ jobs:
     steps:
       - name: Checkout Repo
         uses: actions/checkout@v4
-      - uses: mamba-org/setup-micromamba@v1
+      - uses: mamba-org/setup-micromamba@v2
         with:
           environment-file: ci/environment.yml
           init-shell: >-