Bump prefix-dev/setup-pixi from 0.8.1 to 0.9.1

Bumps [prefix-dev/setup-pixi](https://github.com/prefix-dev/setup-pixi) from 0.8.1 to 0.9.1.
- [Release notes](https://github.com/prefix-dev/setup-pixi/releases)
- [Commits](prefix-dev/setup-pixi@v0.8.1...v0.9.1)

---
updated-dependencies:
- dependency-name: prefix-dev/setup-pixi
  dependency-version: 0.9.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

.github/workflows/testing.yml

@@ -405,7 +405,7 @@ jobs:
         run: ./scripts/ci_run.sh ${{ matrix.project_type }} 5
         shell: bash
       - name: Install Pixi
-        uses: prefix-dev/setup-pixi@v0.8.1
+        uses: prefix-dev/setup-pixi@v0.9.1
         with:
           manifest-path: ${{ env.WORKING_DIR }}/pyproject.toml
           pixi-version: v0.30.0
@@ -441,7 +441,7 @@ jobs:
         run: ./scripts/ci_run.sh ${{ matrix.project_type }} 5
         shell: bash
       - name: Install Pixi
-        uses: prefix-dev/setup-pixi@v0.8.1
+        uses: prefix-dev/setup-pixi@v0.9.1
         with:
           manifest-path: ${{ env.WORKING_DIR }}/pyproject.toml
           pixi-version: v0.30.0