fix CI issues (#10937)

dpkg: error processing package grub-efi-amd64-signed (--configure)

https://github.com/coolsnowwolf/lede/actions/runs/4276705033/jobs/7444992777#step:2:1554

.github/workflows/openwrt-ci.yml

@@ -29,6 +29,7 @@ jobs:
         run: |
           docker rmi `docker images -q`
           sudo -E rm -rf /usr/share/dotnet /etc/mysql /etc/php /etc/apt/sources.list.d /usr/local/lib/android
+          sudo -E apt-mark hold grub-efi-amd64-signed
           sudo -E apt update
           sudo -E apt -y purge azure-cli* docker* ghc* zulu* llvm* firefox google* dotnet* powershell* openjdk* mysql* php* mongodb* dotnet* moby* snap*
           sudo -E apt -y full-upgrade