CI: bump actions/upload-artifact from 4 to 6

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>

Author: dependabot[bot]

.github/workflows/ci-cd.yml

@@ -192,7 +192,7 @@ jobs:
             2>/dev/null || true
 
       - name: Upload lint results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         if: always()
         with:
           name: dclint-results
@@ -612,7 +612,7 @@ jobs:
           echo "safe_name=${SAFE_NAME}" >> $GITHUB_OUTPUT
 
       - name: Upload individual scan result
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: cve-scan-${{ steps.parse.outputs.safe_name }}
           path: ${{ steps.parse.outputs.safe_name }}.json
@@ -736,7 +736,7 @@ jobs:
           echo "CVE scan completed - report generated (non-blocking)"
 
       - name: Upload aggregated results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: cve-scan-results
           path: |
@@ -912,7 +912,7 @@ jobs:
           fi
 
       - name: Upload test result
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         if: always()
         with:
           name: test-result-${{ matrix.service }}
@@ -1010,7 +1010,7 @@ jobs:
           fi
 
       - name: Upload aggregated results
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: docker-compose-test-results
           path: |