fix(terraform): Downgrade provider Proxmox vers v2.9 stable

The v3.0 provider is not yet available as a stable release in the
OpenTofu/Terraform registry. Downgraded to v2.9 which is the latest
stable version.

Also fixed minor yamllint issues in flux.yml:
- Added space after comment marker
- Removed trailing blank line

ansible/roles/k3s-server/tasks/flux.yml

@@ -1,4 +1,5 @@
---- # Install and configure FluxCD
+---
+# Install and configure FluxCD
 
 - name: Check if flux is already installed
   command: k3s kubectl get namespace {{ flux_namespace }}
@@ -49,4 +50,3 @@
       FluxCD installed successfully.
       Configure GitRepository in kubernetes/flux-system/
   when: flux_installed.rc != 0
-

terraform/pve1/main.tf

@@ -4,7 +4,7 @@ terraform {
   required_providers {
     proxmox = {
       source  = "telmate/proxmox"
-      version = "~> 3.0"
+      version = "~> 2.9"
     }
     local = {
       source  = "hashicorp/local"

terraform/pve2/main.tf

@@ -4,7 +4,7 @@ terraform {
   required_providers {
     proxmox = {
       source  = "telmate/proxmox"
-      version = "~> 3.0"
+      version = "~> 2.9"
     }
     local = {
       source  = "hashicorp/local"

terraform/pve3/main.tf

@@ -4,7 +4,7 @@ terraform {
   required_providers {
     proxmox = {
       source  = "telmate/proxmox"
-      version = "~> 3.0"
+      version = "~> 2.9"
     }
     local = {
       source  = "hashicorp/local"