Bump actions/upload-artifact from 6 to 7 (#276)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v6...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

.github/workflows/benchmark.yml

@@ -45,7 +45,7 @@ jobs:
         mkdir -p plots
         benchpkgplot ${{ steps.extract-package-name.outputs.package_name }} --rev="${{github.event.repository.default_branch}},${{github.event.pull_request.head.sha}}" --npart=10 --format=png --input-dir=results/ --output-dir=plots/
     - name: Upload plot as artifact
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: plots
         path: plots

.github/workflows/benchmark_push.yml

@@ -42,7 +42,7 @@ jobs:
         mkdir -p plots
         benchpkgplot ${{ steps.extract-package-name.outputs.package_name }} --rev="v0.1.39,v0.1.40,v0.1.41,$GITHUB_SHA" --npart=10 --format=png --input-dir=results/ --output-dir=plots/
     - name: Upload plot as artifact
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@v7
       with:
         name: plots
         path: plots