[gha] 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/build-azl3-arm-raw.yml

@@ -87,7 +87,7 @@ jobs:
           sudo chmod -R 755 workspace/ || true
           find workspace/*/imagebuild/*/ -name "*.raw*" -exec chmod 777 {} \; || true
       - name: GitHub Upload Release Artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: azl3-arm-raw-image
           path: |

.github/workflows/build-elxr12-arm-raw.yml

@@ -94,7 +94,7 @@ jobs:
           find workspace/*/imagebuild/*/ -name "*.raw*" -exec chmod 777 {} \; || true
 
       - name: GitHub Upload Release Artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: elxr12-arm-raw-image
           path: |

.github/workflows/build-ubuntu24-arm-raw.yml

@@ -88,7 +88,7 @@ jobs:
           find workspace/*/imagebuild/minimal/ -name "*.raw*" -exec chmod 777 {} \; || true
 
       - name: GitHub Upload Release Artifacts
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: ubuntu24-arm-raw-image
           path: |

.github/workflows/unit-test-and-coverage-gate.yml

@@ -76,7 +76,7 @@ jobs:
 
       - name: Upload coverage artifacts
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: coverage-${{ github.run_id }}
           path: |