[4.8] Add support to disable installation of DO agent (#322)

* add $disable_agent support

Based on https://docs.digitalocean.com/products/droplets/how-to/manage-agent/ with_droplet_agent parameter

* fix: correct api call to false bool

* Update Droplet.php

---------

Co-authored-by: Graham Campbell <GrahamCampbell@users.noreply.github.com>

src/Api/Droplet.php

@@ -99,12 +99,13 @@ public function getById(int $id)
      * @param bool         $monitoring
      * @param array        $volumes
      * @param array        $tags
+     * @param bool         $disableAgent
      *
      * @throws ExceptionInterface
      *
      * @return DropletEntity|DropletEntity[]|null
      */
-    public function create($names, string $region, string $size, $image, bool $backups = false, bool $ipv6 = false, $vpcUuid = false, array $sshKeys = [], string $userData = '', bool $monitoring = true, array $volumes = [], array $tags = [])
+    public function create($names, string $region, string $size, $image, bool $backups = false, bool $ipv6 = false, $vpcUuid = false, array $sshKeys = [], string $userData = '', bool $monitoring = true, array $volumes = [], array $tags = [], bool $disableAgent = false)
     {
         $data = \is_array($names) ? ['names' => $names] : ['name' => $names];
 
@@ -117,6 +118,10 @@ public function create($names, string $region, string $size, $image, bool $backu
             'monitoring' => $monitoring ? 'true' : 'false',
         ]);
 
+        if ($disableAgent) {
+            $data['with_droplet_agent'] = 'false';
+        }
+
         if (0 < \count($sshKeys)) {
             $data['ssh_keys'] = $sshKeys;
         }