Bump jorelali/setup-elm from 5 to 6 (#18777)

Bumps [jorelali/setup-elm](https://github.com/jorelali/setup-elm) from 5 to 6.
- [Release notes](https://github.com/jorelali/setup-elm/releases)
- [Commits](https://github.com/jorelali/setup-elm/compare/v5...v6)

---
updated-dependencies:
- dependency-name: jorelali/setup-elm
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/samples-elm.yaml

@@ -22,7 +22,7 @@ jobs:
           - samples/openapi3/client/elm
     steps:
       - uses: actions/checkout@v4
-      - uses: jorelali/setup-elm@v5
+      - uses: jorelali/setup-elm@v6
         with:
           elm-version: 0.19.1
       - name: Build