Fix(plugins): Fix deprecation warning after reformatting

[gmuloc]

Change Summary

f string is missing ..

Related Issue(s)

Fixes issue reported from the field

Component(s) name

plugins

Proposed changes

Making fstring great again

How to test

run with python 3.9 and see the correct message

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-4183
# Activate the virtual environment
source test-avd-pr-4183/bin/activate
# Install all requirements including PyAVD
pip install "pyavd[ansible] @ git+https://github.com/gmuloc/avd.git@fix-error-message#subdirectory=python-avd" --force
# Install Ansible collection
ansible-galaxy collection install git+https://github.com/gmuloc/avd.git#/ansible_collections/arista/avd/,fix-error-message --force
# Optional: Install AVD examples
cd test-avd-pr-4183
ansible-playbook arista.avd.install_examples

[carlbuchmann]

LGTM!