Bump mamba-org/setup-micromamba from 1.9.0 to 2.0.0

Bumps [mamba-org/setup-micromamba](https://github.com/mamba-org/setup-micromamba) from 1.9.0 to 2.0.0.
- [Release notes](https://github.com/mamba-org/setup-micromamba/releases)
- [Commits](mamba-org/setup-micromamba@v1.9.0...v2.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/testing.yml

@@ -33,7 +33,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - name: Set up micromamba
-        uses: mamba-org/setup-micromamba@v1.9.0
+        uses: mamba-org/setup-micromamba@v2.0.0
         with:
           # the create command looks like this:
           # `micromamba create -n test-env python=<the corresponding version> kim-api=2.3.0`