[XPU][CI] fix ci update logs bug (#7912)

* Add ffmpeg installation to Dockerfile.xpu

* add case,DLTP-54994

Author: plusNew001

.github/workflows/_xpu_4cards_case_test.yml

@@ -230,6 +230,7 @@ jobs:
 
       - name: Upload case logs
         if: always()
+        continue-on-error: true
         uses: actions/upload-artifact@v6
         with:
           name: xpu-4cards-case-logs

.github/workflows/_xpu_8cards_case_test.yml

@@ -218,6 +218,7 @@ jobs:
 
       - name: Upload case logs
         if: always()
+        continue-on-error: true
         uses: actions/upload-artifact@v6
         with:
           name: xpu-8cards-case-logs