tests: make azure.sh easier to run locally

We've dropped Jenkins already and this change helps by setting
CI variables to a default value in case they're not present.

test/cases/azure.sh

@@ -3,8 +3,8 @@ set -euo pipefail
 
 source /etc/os-release
 DISTRO_CODE="${DISTRO_CODE:-${ID}_${VERSION_ID//./}}"
-BRANCH_NAME="${BRANCH_NAME:-${CI_COMMIT_BRANCH}}"
-BUILD_ID="${BUILD_ID:-${CI_BUILD_ID}}"
+BRANCH_NAME="${CI_COMMIT_BRANCH:-'local'}"
+BUILD_ID="${CI_BUILD_ID:-$(uuidgen)}"
 HYPER_V_GEN="${HYPER_V_GEN:-V1}"
 
 # Colorful output.