update: Added Longhorn installation process and updated memory allocation for VMs

update: Added 'git' and 'vagrant' to required tools in pre-flight checks

fix: configured k3s install to use internal nic for flanel network

vagrant/dev/ubuntu/k8s/nginx-test/pvc.yaml

@@ -0,0 +1,12 @@
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: nginx-data-pvc
+  namespace: default
+spec:
+  accessModes:
+    - ReadWriteOnce
+  storageClassName: longhorn
+  resources:
+    requests:
+      storage: 1Gi