ci/tests: Change the way artifacts are collected

We want to be able to safely gather any artifacts without worrying about
any possible secrets leaking. Every artifacts that we want to upload
will now have to be placed in /tmp/artifacts which will then be uploaded
to S3 by the executor and link to the artifacts will be provided in the
logs. Only people with access to our AWS account can see them.

test/cases/azure.sh

@@ -94,11 +94,7 @@ ARCH=$(uname -m)
 TEST_ID="$DISTRO_CODE-$ARCH-$BRANCH_NAME-$BUILD_ID"
 IMAGE_KEY=image-${TEST_ID}
 
-# Jenkins sets WORKSPACE to the job workspace, but if this script runs
-# outside of Jenkins, we can set up a temporary directory instead.
-if [[ ${WORKSPACE:-empty} == empty ]]; then
-    WORKSPACE=$(mktemp -d)
-fi
+ARTIFACTS="${ARTIFACTS:-/tmp/artifacts}"
 
 # Set up temporary files.
 AZURE_CONFIG=${TEMPDIR}/azure.toml
@@ -119,7 +115,7 @@ smoke_test_check () {
 # Get the compose log.
 get_compose_log () {
     COMPOSE_ID=$1
-    LOG_FILE=${WORKSPACE}/osbuild-${ID}-${VERSION_ID}-azure.log
+    LOG_FILE=${ARTIFACTS}/osbuild-${ID}-${VERSION_ID}-azure.log
 
     # Download the logs.
     sudo composer-cli compose log "$COMPOSE_ID" | tee "$LOG_FILE" > /dev/null
@@ -128,7 +124,7 @@ get_compose_log () {
 # Get the compose metadata.
 get_compose_metadata () {
     COMPOSE_ID=$1
-    METADATA_FILE=${WORKSPACE}/osbuild-${ID}-${VERSION_ID}-azure.json
+    METADATA_FILE=${ARTIFACTS}/osbuild-${ID}-${VERSION_ID}-azure.json
 
     # Download the metadata.
     sudo composer-cli compose metadata "$COMPOSE_ID" > /dev/null