Bump cache stamp
Build times have regressed and we are spending a lot of time doing
caching stuff.
set -e
manual_stamp_file=target/ci_manual_stamp
-manual_stamp=6 # Change this to force a clean build on CI
+manual_stamp=7 # Change this to force a clean build on CI
if [ -f $manual_stamp_file ]; then
if echo "$manual_stamp" | cmp -s $manual_stamp_file -; then
