ox-ruby: provide absolute path to Ruzzy (#14108)

Ruzzy is located in /usr/bin/*
https://github.com/google/oss-fuzz/blob/4b541c7c4d0671a59a9bee4999e6fc4c36483bc1/infra/base-images/base-runner/Dockerfile#L115

It should probably be placed in /usr/local/bin/ similar to the rest of
the commands:
https://github.com/google/oss-fuzz/blob/4b541c7c4d0671a59a9bee4999e6fc4c36483bc1/infra/base-images/base-runner/Dockerfile#L138

Testing this to see if it works.

Author: DavidKorczynski

projects/ox-ruby/build.sh

@@ -46,7 +46,7 @@ echo "Showing this dir:"
 ls -la \$this_dir
 
 
-ruzzy \$this_dir/fuzz_parse.rb \$@""" > $OUT/fuzz_parse
+/usr/bin/ruzzy \$this_dir/fuzz_parse.rb \$@""" > $OUT/fuzz_parse
 
 chmod +x $OUT/fuzz_parse