define JSONDecoder() outside of for loop in load() (#159)

this PR defines a variable, `decoder`, which represents the
`JSONDecoder` class, rather than doing it in the for loop in `load()`

Signed-off-by: Elijah Wright <git@elijahs.space>

Author: elijah-wright

Sources/ContainerPersistence/EntityStore.swift

@@ -101,12 +101,13 @@ public actor FilesystemEntityStore<T>: EntityStore where T: Codable & Identifiab
     private static func load(path: URL, log: Logger) throws -> Index {
         let directories = try FileManager.default.contentsOfDirectory(at: path, includingPropertiesForKeys: nil)
         var index: FilesystemEntityStore<T>.Index = Index()
+        let decoder = JSONDecoder()
 
         for entityUrl in directories {
             do {
                 let metadataUrl = entityUrl.appendingPathComponent(metadataFilename)
                 let data = try Data(contentsOf: metadataUrl)
-                let entity = try JSONDecoder().decode(T.self, from: data)
+                let entity = try decoder.decode(T.self, from: data)
                 index[entity.id] = entity
             } catch {
                 log.warning(