Reapply "ci: try installing qemu 7.0 from canonical server backports"

This reverts commit 89cc28e.

Author: yamt

.github/workflows/ci.yml

@@ -447,7 +447,12 @@ jobs:
 
     - name: Install QEMU
       if: matrix.arch != 'native' && matrix.arch != 'i386'
+      # install newer qemu from
+      # https://launchpad.net/%7Ecanonical-server/+archive/ubuntu/server-backports/
+      # https://github.com/yamt/toywasm/pull/53#issuecomment-1605899935
       run: |
+        sudo apt-get update && sudo apt-get install -y software-properties-common
+        sudo add-apt-repository -y ppa:canonical-server/server-backports
         sudo apt-get update && sudo apt-get install -y qemu-user-static
 
     - name: toywasm --version