Bump actions/upload-artifact from 6 to 7 (signalfx#2257)

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v6...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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Jina Jain <jjain@splunk.com>

Author: dependabot[bot]

.github/workflows/functional_test.yaml

@@ -134,7 +134,7 @@ jobs:
 
       - name: Upload Kubernetes Cluster debug info
         if: always() && (steps.run-functional-tests.outcome == 'failure' || env.KUBERNETES_DEBUG_INFO == 'true')
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: k8s-debug-info-${{ matrix.k8s-minikube-version }}-${{ matrix.container_runtime }}-splunk-${{ matrix.splunk_version }}
           path: tools/splunk_kubernetes_debug_info_*

.github/workflows/functional_test_v2.yaml

@@ -90,14 +90,14 @@ jobs:
           ./splunk_kubernetes_debug_info.sh
       - name: Upload Kubernetes Cluster debug info
         if: always() && (steps.run-functional-tests.outcome == 'failure' || env.KUBERNETES_DEBUG_INFO == 'true')
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: k8s-debug-info-${{ matrix.test-job }}-${{ matrix.k8s-kind-version }}
           path: tools/splunk_kubernetes_debug_info_*
           retention-days: 5
       - name: Upload updated files artifact
         if: always() && env.UPDATE_EXPECTED_RESULTS == 'true'
-        uses: actions/upload-artifact@v6
+        uses: actions/upload-artifact@v7
         with:
           name: updated_expected_results-${{ matrix.test-job }}-${{ matrix.k8s-kind-version }}
           path: ./functional_tests/**/*.yaml