Introduce idiomatic practices for affected areas from previous commits

**Added:**

- Structured HTTP Proxy Configuration Block - Added a structured block in
  `http_proxy.yml` for managing HTTP proxy settings, aligning with Ansible's
  recommended practices. This includes creating directories and deploying
  configuration files in a clear, modular fashion.
- Conditional Execution for Proxy Setup - Implemented conditional execution
  for the proxy setup in `http_proxy.yml`, utilizing `proxy_env` to adhere
  to Ansible's best practices for conditional tasks.
- Improved PXE-Boot System Check Block - Introduced a more structured approach
  in `main.yml` for checking PXE-booted systems, enhancing readability and
  maintainability.

**Changed:**

- Adopted Ansible Builtin Modules - Transitioned existing tasks to use
  `ansible.builtin` modules, ensuring compatibility and future-proofing the
  role.
- Refined Task Grouping - Reorganized tasks into logical blocks, improving
  the overall structure and readability, and showcasing Ansible's capabilities
  for efficient task management.
- Updated K3s Service Configuration - Modified the K3s service configuration
  task in `main.yml` for a more streamlined approach using Ansible's template
  module, reflecting community-driven best practices.

**Removed:**

- Streamlined Task Definitions - Optimized task definitions to reduce
  redundancy, focusing on clarity and adherence to the evolving Ansible
  community standards.

roles/k3s_agent/tasks/http_proxy.yml

@@ -1,5 +1,4 @@
 ---
-
 - name: Create k3s-node.service.d directory
   file:
     path: '{{ systemd_dir }}/k3s-node.service.d'