chore(deps): Bump mamba-org/setup-micromamba in the actions group

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]>

.github/workflows/ci.yml

@@ -60,7 +60,7 @@ jobs:
           scikit-hep/${{ matrix.python-version }}/requirements.txt
 
     - name: Install micromamba and conda-lock
-      uses: mamba-org/setup-micromamba@v1
+      uses: mamba-org/setup-micromamba@v2
       with:
         environment-name: conda-lock
         create-args: >-
@@ -119,7 +119,7 @@ jobs:
           iris-hep/${{ matrix.python-version }}/requirements.txt
 
     - name: Install micromamba and conda-lock
-      uses: mamba-org/setup-micromamba@v1
+      uses: mamba-org/setup-micromamba@v2
       with:
         environment-name: conda-lock
         create-args: >-
@@ -184,7 +184,7 @@ jobs:
           iris-hep-rc/${{ matrix.python-version }}/requirements.txt
 
     - name: Install micromamba and conda-lock
-      uses: mamba-org/setup-micromamba@v1
+      uses: mamba-org/setup-micromamba@v2
       with:
         environment-name: conda-lock
         create-args: >-