chore(ci): bump actions/upload-artifact from 4 to 7

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v7)

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

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

Author: dependabot[bot]

.github/workflows/evals.yml

@@ -56,7 +56,7 @@ jobs:
 
       - name: Upload eval results
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: promptfoo-evals
           path: |

.github/workflows/mutation.yml

@@ -37,7 +37,7 @@ jobs:
 
       - name: Upload mutation report
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: mutation-report
           path: reports/mutation/**

.github/workflows/scorecard.yml

@@ -37,7 +37,7 @@ jobs:
           sarif_file: results.sarif
 
       - name: Upload results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: ossf-scorecard-results
           path: results.sarif