Refactor(eos_cli_config_gen)!: Make router_traffic_engineering.enabled required

[gmuloc]

Change Summary

As described in the issue - right now AVD 4.0.0 renders config with an empty dict which we don't want.

Related Issue(s)

Fixes #3281

Component(s) name

arista.avd.eos_cli_config_gen

Proposed changes

Make enabled required in schema and fix the template logic

How to test

molecule

Checklist

Repository Checklist

• My code has been rebased from devel before I start
• I have read the CONTRIBUTING document.
• My change requires a change to the documentation and documentation have been updated accordingly.
• I have updated molecule CI testing accordingly. (check the box if not applicable)

[github-actions]

Review docs on Read the Docs

To test this pull request:

# Create virtual environment for this testing below the current directory
python -m venv test-avd-pr-4403
# Activate the virtual environment
source test-avd-pr-4403/bin/activate
# Install all requirements including PyAVD
pip install "pyavd[ansible] @ git+https://github.com/gmuloc/avd.git@issue/3281#subdirectory=python-avd" --force
# Point Ansible collections path to the Python virtual environment
export ANSIBLE_COLLECTIONS_PATH=$VIRTUAL_ENV/ansible_collections
# Install Ansible collection
ansible-galaxy collection install git+https://github.com/gmuloc/avd.git#/ansible_collections/arista/avd/,issue/3281 --force
# Optional: Install AVD examples
cd test-avd-pr-4403
ansible-playbook arista.avd.install_examples

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[Vibhu-gslab]

LGTM!