Free up CI runner disk space before running UI tests.

ci_scripts/free_space.sh

@@ -0,0 +1,15 @@
+#!/usr/bin/env bash
+
+#
+# Taken from 
+# https://github.com/actions/runner-images/issues/2840#issuecomment-790492173
+#
+
+set -ux
+
+df -h
+sudo rm -rf /usr/share/dotnet
+sudo rm -rf /opt/ghc
+sudo rm -rf "/usr/local/share/boost"
+sudo rm -rf "$AGENT_TOOLSDIRECTORY"
+df -h