Refactor to remove slices and environments, replace with instances.

app/Models/Environment.php

@@ -1,28 +0,0 @@
-<?php
-
-namespace App\Models;
-
-use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\Relations\BelongsTo;
-use Illuminate\Database\Eloquent\Relations\HasMany;
-use Illuminate\Database\Eloquent\Relations\HasManyThrough;
-
-class Environment extends Model
-{
-    protected $guarded = [];
-
-    public function application(): BelongsTo
-    {
-        return $this->belongsTo(Application::class);
-    }
-
-    public function slices(): HasMany
-    {
-        return $this->hasMany(Slice::class);
-    }
-
-    public function services(): HasManyThrough
-    {
-        return $this->hasManyThrough(Service::class, Slice::class);
-    }
-}