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

Bumps [mamba-org/setup-micromamba](https://github.com/mamba-org/setup-micromamba) from 2 to 3.
- [Release notes](https://github.com/mamba-org/setup-micromamba/releases)
- [Commits](mamba-org/setup-micromamba@v2...v3)

---
updated-dependencies:
- dependency-name: mamba-org/setup-micromamba
  dependency-version: '3'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/mac.yml

@@ -35,7 +35,7 @@ jobs:
 
       - uses: actions/checkout@v6
 
-      - uses: mamba-org/setup-micromamba@v2
+      - uses: mamba-org/setup-micromamba@v3
         with:
           init-shell: bash
           environment-file: .github/workflows/mac/environment.yml