chore: remove logic to upgrade az (#4501)

Co-authored-by: Charlie Li <[email protected]>

vhdbuilder/packer/init-variables.sh

@@ -108,13 +108,6 @@ fi
 if [[ ${ARCHITECTURE,,} == "arm64" ]]; then
   ARM64_OS_DISK_SNAPSHOT_NAME="arm64_osdisk_snapshot_${CREATE_TIME}_$RANDOM"
   SIG_IMAGE_NAME=${SIG_IMAGE_NAME//./}Arm64
-  # Only az published after April 06 2022 supports --architecture for command 'az sig image-definition create...'
-  azversion=$(az version | jq '."azure-cli"' | tr -d '"')
-  if [[ "${azversion}" < "2.35.0" ]]; then
-    az upgrade -y
-    az login --identity
-    az account set -s ${SUBSCRIPTION_ID}
-  fi
 fi
 
 echo "Using finalized SIG_IMAGE_NAME: ${SIG_IMAGE_NAME}, SIG_GALLERY_NAME: ${SIG_GALLERY_NAME}"