[FIX] direxec should not try to execute directories

[ap-wtioit]

In f931b534872fed96e9037ad31eb5b90ada4b3111 direxec was converted from bash to python. In the python version we should not try to execute directories. As the execute flag for directories only means that the user can change into the directory not that the directory is an executable.

This happens when a user adds a custom python script to entrypoint.d and runs doodba built with COMPILE: "true". for this case a __pycache__ directory is created in /opt/odoo/custom/entrypoint.d/ that causes the following error:

PermissionError: [Errno 13] Permission denied: '/opt/odoo/custom/entrypoint.d/__pycache__'

Info @wt-io-it

[ap-wtioit]

Updated the merge request to reflect the information gathered by the investigation of the #509 issue after discovering and fixing the cause.