Bump actions/upload-artifact from 4 to 6 (#19)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v4...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  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>

Author: dependabot[bot]

.github/workflows/release.yml

@@ -165,7 +165,7 @@ jobs:
           format: spdx-json
           output-file: ${{ matrix.image }}-sbom.spdx.json
       - name: Upload SBOM
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: sbom-${{ matrix.image }}
           path: ${{ matrix.image }}-sbom.spdx.json
@@ -189,7 +189,7 @@ jobs:
         run: |
           helm package helm/recotem/ --version "${TAG_REF#v}" --app-version "${TAG_REF#v}"
       - name: Upload Helm package
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: helm-chart
           path: recotem-*.tgz

.github/workflows/run-test.yml

@@ -27,7 +27,7 @@ jobs:
         working-directory: frontend
         run: npx vitest run --coverage --coverage.thresholds.lines=80
       - name: Save frontend coverage
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: frontend-coverage
           path: frontend/coverage/lcov.info
@@ -91,7 +91,7 @@ jobs:
         run: docker compose -f compose.yaml -f compose.ci.yaml down -v --remove-orphans
       - name: Save test artifacts
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           path: |
             frontend/playwright-report/
@@ -180,7 +180,7 @@ jobs:
               (echo "Generated types are out of date. Run: npm run generate:types" && exit 1)
           fi
       - name: Save coverage
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: pytest-coverage-py${{ matrix.python-version }}
           path: backend/recotem/coverage.xml