use correct gh_dir env for zombienet (#4346)

25 jobs for master in 46 minutes and 4 seconds (queued for 7 seconds)
Name Stage Failure
failed
zombienet-tests-malus-dispute-valid Deploy


exit code 3
+ EXIT_STATUS=3
+ set +x

2021-11-22 13:17:49 - INFO - Exit status is 3
Cleaning up file based variables
ERROR: Job failed: command terminated with exit code 1
failed
spellcheck Test
[2021-11-22T12:36:23Z INFO  cargo_spellcheck::action] ✅ /builds/parity/polkadot/node/jaeger/src/errors.rs
[2021-11-22T12:36:23Z INFO cargo_spellcheck::action] ✅ /builds/parity/polkadot/node/jaeger/src/config.rs
[2021-11-22T12:36:23Z INFO cargo_spellcheck::action] ✅ /builds/parity/polkadot/node/jaeger/src/spans.rs

real 2m6.871s
user 15m41.099s
sys 6m28.121s
Cleaning up file based variables
ERROR: Job failed: exit code 1