Bump prefix-dev/setup-pixi from 0.8.3 to 0.8.4 in the actions group

Bumps the actions group with 1 update: [prefix-dev/setup-pixi](https://github.com/prefix-dev/setup-pixi).


Updates `prefix-dev/setup-pixi` from 0.8.3 to 0.8.4
- [Release notes](https://github.com/prefix-dev/setup-pixi/releases)
- [Commits](prefix-dev/setup-pixi@v0.8.3...v0.8.4)

---
updated-dependencies:
- dependency-name: prefix-dev/setup-pixi
  dependency-version: 0.8.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: actions
...

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -31,7 +31,7 @@ jobs:
         with:
           fetch-depth: 0
 
-      - uses: prefix-dev/setup-pixi@v0.8.3
+      - uses: prefix-dev/setup-pixi@v0.8.4
         with:
           pixi-version: v0.39.4
           cache: true