[bugfix] more little edit fixes (#3633)

* fix slice size calculation

* stop attached status edit slice getting cached

internal/cache/db.go

@@ -1320,6 +1320,7 @@ func (c *Caches) initStatus() {
 		s2.Mentions = nil
 		s2.Emojis = nil
 		s2.CreatedWithApplication = nil
+		s2.Edits = nil
 
 		return s2
 	}

internal/gtsmodel/status.go

@@ -281,7 +281,7 @@ func (s *Status) AllAttachmentIDs() []string {
 	}
 
 	// Get count of attachment IDs.
-	total += len(s.Attachments)
+	total += len(s.AttachmentIDs)
 	for _, edit := range s.Edits {
 		total += len(edit.AttachmentIDs)
 	}