Use find instead of glob in validation script

Because they have different behaviour when there's no matches!

Author: croyzor

brat/tools/validate.sh

@@ -22,7 +22,7 @@ for json in test/compilation/output/*.json; do
     fi
 done
 
-for invalid_json in test/compilation/output/*.json.invalid; do
+for invalid_json in $(find . -maxdepth 1 -name "test/compilation/output/*.json.invalid"); do
     if (hugr_validator < $invalid_json 2>/dev/null > /dev/null); then
         UNEXPECTED_PASSES="$UNEXPECTED_PASSES $invalid_json"
     fi
@@ -51,4 +51,4 @@ if [ "$UNEXPECTED_PASSES" != "" ]; then
     echo -e $RED "There were unexpected passes: $UNEXPECTED_PASSES" $NO_COLOUR
     RESULT=1
 fi
-exit $RESULT
+exit $RESULT