Bump mamba-org/setup-micromamba from 1 to 2 in the actions group (#23)

Bumps the actions group with 1 update: [mamba-org/setup-micromamba](https://github.com/mamba-org/setup-micromamba).


Updates `mamba-org/setup-micromamba` from 1 to 2
- [Release notes](https://github.com/mamba-org/setup-micromamba/releases)
- [Commits](mamba-org/setup-micromamba@v1...v2)

---
updated-dependencies:
- dependency-name: mamba-org/setup-micromamba
  dependency-type: direct:production
  update-type: version-update:semver-major
  dependency-group: actions
...

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

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -57,7 +57,7 @@ jobs:
           fetch-depth: 0
 
       - name: Setup micromamba
-        uses: mamba-org/setup-micromamba@v1
+        uses: mamba-org/setup-micromamba@v2
         with:
           environment-file: ci/requirements/environment.yaml
           environment-name: tests