[full-ci][tests-only] use global cache for web and core repos usage (#4309)

tests/config/drone/check_web_cache.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+source .drone.env
+
+echo "Checking web version - $WEB_COMMITID in cache"
+
+URL="$CACHE_ENDPOINT/$CACHE_BUCKET/ocis/web-test-runner/$WEB_COMMITID/README.md"
+
+echo "Checking for the web cache at '$URL'."
+
+if curl --output /dev/null --silent --head --fail "$URL"
+then
+	echo "Web with commit id $WEB_COMMITID already available in cache"
+	# https://discourse.drone.io/t/how-to-exit-a-pipeline-early-without-failing/3951
+	# exit a Pipeline early without failing
+	exit 78
+else
+	echo "Web with $WEB_COMMITID not available in cache"
+fi