ci: fix luatest version

"Test" workflow installs latest luatest, yet "Reusable test" installs
luatest 0.5.7. Latest e2cdb56 commit had introduced tests which use
some luatest master utils. These tests fails on "Reusable test",
see [1].

1. https://github.com/tarantool/tarantool/actions/runs/5411519721/jobs/9835738155

Follows #110

deps.sh

@@ -4,6 +4,6 @@
 set -e
 
 # Test dependencies:
-tarantoolctl rocks install luatest 0.5.7
+tarantoolctl rocks install luatest
 tarantoolctl rocks install luacov 0.13.0
 tarantoolctl rocks install luacheck 0.26.0