Add demo mode restriction to CaptchaToken destroy method.

This commit adds a check to the `destroy` method in the `CaptchaTokenService`. It uses the `Helpers::isDemoModeAndUserDenyUpdate` function to prevent users from deleting tokens while the application is in demo mode. This was added to protect the application's state during presentations or demos.

app/Models/CaptchaToken.php

@@ -4,6 +4,7 @@ namespace App\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Database\Eloquent\SoftDeletes;
 
@@ -36,4 +37,9 @@ final class CaptchaToken extends Model
     {
         return $this->hasMany(Captcha::class);
     }
+
+    public function user(): BelongsTo
+    {
+        return $this->belongsTo(User::class);
+    }
 }