gpg-agent missing

[coaxial]

Describe the bug

When running the role, the "(Debian/Ubuntu) Add NGINX signing key" task fails on Ubuntu 20.04 because gpg-agent is missing.

To reproduce

Steps to reproduce the behavior:

1. Run the role against the geerlingguy/ubuntu2004-ansible:latest docker container
2. See how the task fails because gpg-agent isn't installed

Expected behavior

The task should not error

Your environment

• Version of the NGINX role or specific commit: 0.23.1
• Version of Ansible: 5.0.6
• Target deployment platform: geerlingguy/ubuntu2004-ansible:latest docker container

Additional context