Get rid of the wait_for_deployments.sh script

[zadigus]

Devspace currently has no built-in way to wait until the deployment is ready, as one would need e.g. on a ci / cd pipeline where one would first wait until the deployments are fully successful before starting with staging tests like integration, acceptance, and load tests. The devspace team is working on it, so when it is solved, we will just remove the script.

When we remove the wait_for_deployments.sh script, we need to adapt our pipelines too.

The corresponding devspace issue can be consulted here: devspace-sh/devspace#954.

[zadigus]

For the time being, we keep the script. I am not convinced of the --wait flag to devspace deploy.