Add auto-source support for updateSiteDeploymentScript Method

[mehrancodes]

In order to enhance the deployment process and provide more flexibility, we need to add the ability to make .env variables available to the deployment script in the forge-sdk. This can be achieved by adding a fourth boolean argument to the updateSiteDeploymentScript method.

Current Behavior:
Currently, the method signature is:

$service->forge->updateSiteDeploymentScript($serverId, $siteId, $content);

Desired Behavior:
The proposed method signature is:

$service->forge->updateSiteDeploymentScript($serverId, $siteId, $content, $autoSource);

Where $autoSource is a boolean indicating whether to automatically source the .env variables.

[jbrooksuk]

This was done in #167 and is available in https://github.com/laravel/forge-sdk/releases/tag/v3.14.0