[Az.Functions] The docs of cmdlets which are not included in functionsToExport list show up

### Description

Some cmdlets in Az.Functions are not included in the list of functionsToExport. So Az.Functions.psd1 don't expose them to customer.
https://github.com/Azure/azure-powershell/blob/0620ae913953b155ab92ae4c0371735c7f48c4e2/src/Functions/README.md?plain=1#L107:L123

But their docs and scripts still exist in docs/export folder, they may need to be hided.

Here is the cmdlet list that we detected were not included in functionsToExport but their docs exists.

### Issue script & Debug output

```PowerShell
None
```

### Environment data

```PowerShell
None
```

### Module versions

```PowerShell
None
```

### Error output

_No response_