Runner helper images missing entrypoint

Summary

The runner helper images in both our GitLab registry and the Docker registry are missing the entrypoint. This is a major issue because the Entrypoint script is responsible for, among other things, importing custom certificates.

Based on @ggeorgiev_gitlab's comment in this docs MR, this is likely a regression.

This issue seems to impact the executorkubernetes and executordocker images.

Steps to reproduce

1. Register a runner with docker executor
2. Map the cert volume as per our docs - trusting the cert for other CICD stages
3. Accessing the cache fails with x509: certificate signed by unknown authority

Actual behavior

None of the runner helper images have the entrypoint specified which prevents custom certs from being imported.

Expected behavior

The entrypoint should be specified so that things like custom certs can be added to the container.

Possible fixes