Bump actions/upload-artifact from 4 to 7 (#186)

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
...

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

Author: dependabot[bot]

.github/workflows/CI.yml

@@ -39,7 +39,7 @@ jobs:
           echo "sha256=${SHA256}" >> $GITHUB_ENV
  
       - name: Upload package artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: ISO-Kubuntu
           path: ${{ github.workspace }}/output/kubuntu-25.10-${{ env.kver }}-t2-questing.iso
@@ -140,7 +140,7 @@ jobs:
           echo "sha256=${SHA256}" >> $GITHUB_ENV
  
       - name: Upload package artifact
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v7
         with:
           name: ISO-Ubuntu-Unity
           path: ${{ github.workspace }}/output/ubuntu-unity-25.10-${{ env.kver }}-t2-questing.iso