feat: add steam_disk_space egg feature to SteamCMD eggs

A new egg feature modal was introduced in Panel v1.7.0 triggering when server has run out of disk space to provide more user-friendly instructions to both admins and normal users. This is unique to SteamCMD specific errors.

game_eggs/steamcmd_servers/rust/rust_autowipe/egg-rust-autowipe.json

@@ -8,7 +8,9 @@
     "name": "Rust Autowipe",
     "author": "support@pterodactyl.io",
     "description": "The only aim in Rust is to survive. To do this you will need to overcome struggles such as hunger, thirst and cold. Build a fire. Build a shelter. Kill animals for meat. Protect yourself from other players, and kill them for meat. Create alliances with other players and form a town. Do whatever it takes to survive.",
-    "features": null,
+    "features": [
+        "steam_disk_space"
+    ],
     "images": [
         "quay.io\/pterodactyl\/core:rust"
     ],

game_eggs/steamcmd_servers/rust/rust_staging/egg-rust-staging.json

@@ -8,7 +8,9 @@
     "name": "Rust Staging",
     "author": "root@smc.li",
     "description": "The only aim in Rust is to survive. To do this you will need to overcome struggles such as hunger, thirst and cold. Build a fire. Build a shelter. Kill animals for meat. Protect yourself from other players, and kill them for meat. Create alliances with other players and form a town. Do whatever it takes to survive.",
-    "features": null,
+    "features": [
+        "steam_disk_space"
+    ],
     "images": [
         "quay.io\/pterodactyl\/core:rust"
     ],