Install-AzAksCliTool does not set executable bit on Linux

### Description

Install-AzAksCliTool does not set executable bit on Linux

After running:

-rw-r--r-- 1 me me 56381592 Aug 19 19:44 kubectl

### Issue script & Debug output

```PowerShell
NA
```

### Environment data

```PowerShell
Name Value
---- -----
PSVersion 7.4.2
PSEdition Core
GitCommitId 7.4.2
OS Ubuntu 24.04.2 LTS
Platform Unix
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0…}
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
WSManStackVersion 3.0
```

### Module versions

```PowerShell
PS /home/me> Get-Module Az.Aks

ModuleType Version PreRelease Name ExportedCommands
---------- ------- ---------- ---- ----------------
Script 7.0.0 Az.Aks {Disable-AzAksAddOn, Enable-AzAksAddOn, Get-AzAks…
```

### Error output

```PowerShell

```