[Bug]: Can add wss:// connection to rpcurl

### Describe the bug

I'm trying to add a websocket rpc url from a rpc provider but the UI is enforcing https://

### Expected behavior

should support https:// or wss://

### Screenshots/Recordings


### Steps to reproduce

1. add an rpcurl to a network that metamask supports websockets for
2. try a websocket from infura
3. see the error

### Error messages or log output

_No response_

### Detection stage

In production (default)

### Version

12.6.0-flask.0

### Build type

Flask

### Browser

Chrome

### Operating system

Linux

### Hardware wallet

_No response_

### Additional context

_No response_

### Severity

- websockets can retrieve logs alot better than polling strategies

Reproduce the issue in the MetaMask UI by adding an RPC URL from an Infura websocket endpoint, then locate the validation that rejects values beginning with wss://. The work is done when both https:// and wss:// RPC URLs are accepted for supported networks and the existing error no longer appears for websocket URLs.

Written by the indexing model from the issue text.