[ci] Fix build error when converting vhdx image. (#17029)

Why I did it
When using sonic-slave-buster to convert sonic-vs.img.gz to vhdx, it also needs reproducible options.
Otherwise it will rebuild sonic-slave-buster because tag different.

Work item tracking
Microsoft ADO (number only): 25615544
How I did it
Add build options to use same sonic-slave docker when generating vhdx image.

How to verify it

.azure-pipelines/azure-pipelines-build.yml

@@ -124,7 +124,7 @@ jobs:
             make $BUILD_OPTIONS target/docker-sonic-vs.gz target/sonic-vs.img.gz target/docker-ptf.gz
             if [ $(Build.Reason) != 'PullRequest' ];then
               gzip -kd target/sonic-vs.img.gz
-              SONIC_RUN_CMDS="qemu-img convert target/sonic-vs.img -O vhdx -o subformat=dynamic target/sonic-vs.vhdx" make sonic-slave-run
+              SONIC_RUN_CMDS="qemu-img convert target/sonic-vs.img -O vhdx -o subformat=dynamic target/sonic-vs.vhdx" make $BUILD_OPTIONS sonic-slave-run
               rm target/sonic-vs.img
             fi
           else