-[GDTCORDirectorySizeTracker calculateDirectoryContentSize] app crash

### Description

This is a crash produced on our app at the login workflow.

Device: iPhone SE (2nd generation)
Operating System Version:18.6.2
Orientation:Portrait
RAM free: 100.28 MB
Disk free: 39.73 GB
Firebase version: 12.0.0

### Reproducing the issue

This issue is not easily reproducible, it is random and not that intermittent

### Firebase SDK Version

12.0.0

### Xcode Version

16.4

### Installation Method

CocoaPods

### Firebase Product(s)

Crashlytics

### Targeted Platforms

iOS

### Relevant Log Output

```shell

```

### If using Swift Package Manager, the project's Package.resolved

Expand Package.resolved snippet

```json

Replace this line with the contents of your Package.resolved.

```

### If using CocoaPods, the project's Podfile.lock

Expand Podfile.lock snippet

```yml

Replace this line with the contents of your Podfile.lock!

```