fix(valheim): drop MaxPlayers; Valheim has no -maxplayers option

The draft passed -maxplayers, which the server ignores (Valheim's limit is
fixed), so changing the setting would do nothing.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

games/valheim/game.yaml

@@ -2,7 +2,7 @@
 id: valheim
 name: Valheim
 defaultDockerImage: cm2network/steamcmd
-defaultStartupCommand: args=(-name "${SERVER_NAME:-GBRHosting - Valheim}" -port 2456 -world "${WORLD_NAME:-Dedicated}" -savedir /server); [ -n "${SERVER_PASSWORD}" ] && args+=(-password "${SERVER_PASSWORD}"); [ "${CROSSPLAY}" = "true" ] && args+=(-crossplay); [ -n "${MAX_PLAYERS}" ] && args+=(-maxplayers "${MAX_PLAYERS}"); ./valheim_server.x86_64 "${args[@]}"
+defaultStartupCommand: args=(-name "${SERVER_NAME:-GBRHosting - Valheim}" -port 2456 -world "${WORLD_NAME:-Dedicated}" -savedir /server); [ -n "${SERVER_PASSWORD}" ] && args+=(-password "${SERVER_PASSWORD}"); [ "${CROSSPLAY}" = "true" ] && args+=(-crossplay); ./valheim_server.x86_64 "${args[@]}"
 requiredMemoryMb: 4096
 requiredDiskMb: 4096
 defaultPorts:
@@ -13,7 +13,6 @@ installConfig:
   appId: "896660"
 defaultConfig:
   Crossplay: false
-  MaxPlayers: 10
   ServerName: GBRHosting - {SERVER_NAME}
   ServerPassword: ""
   WorldName: Dedicated
@@ -24,11 +23,6 @@ configSchema:
       description: Enable crossplay so Xbox, PlayStation, Nintendo Switch, and Game Pass players can join. A join code is printed to the server log when enabled.
       title: Enable Crossplay
       type: boolean
-    MaxPlayers:
-      category: Gameplay & Rules
-      description: Maximum number of concurrent players allowed on the server.
-      title: Max Players
-      type: integer
     ServerName:
       category: System & General
       description: Display name of the dedicated server. Defaults to "GBRHosting - <your server name>".