Update worker slice gateway pod spec with openvpn server container SecurityContext

### 📜 Description

Review and update worker slice gateway pod spec with openvpn server container SecurityContext (fix permissions - too permissive)

### 👟 Reproduction steps

Create a slice with 2 clusters

### 👍 Expected behavior

Container securitycontext needs to request minimum required permissions - please review and update

### 👎 Actual Behavior

Container spec security context requests too permissive

### 🐚 Relevant log output

_No response_

### Version

_No response_

### 🖥️ What operating system are you seeing the problem on?

Linux

### ✅ Proposed Solution

_No response_

### 👀 Have you spent some time to check if this issue has been raised before?

- [X] I checked and didn't find any similar issue

### Code of Conduct

- [X] I agree to follow this project's Code of Conduct

Locate the worker slice gateway pod specification and the OpenVPN server container definition, then inspect its current SecurityContext and related deployment code. Compare the requested permissions with the minimum required for the container and verify the two-cluster slice reproduction; done means the pod spec no longer requests unnecessary permissions.

Written by the indexing model from the issue text.