ci/slt: create target dir if not exists

Author: benesch

ci/slt/slt.sh

@@ -24,6 +24,8 @@ fi
 
 set -x
 
+mkdir -p target
+
 # TODO(jamii) We can't run test/select4.test without predicate pushdown - it's too slow
 cargo run --release --bin=sqllogictest -- \
     sqllogictest/test/select1.test \