Could not load Ionic.Zlib.CF when running a script using Zlib library functions in Play Mode

How to reproduce:

1. Open the attached “IN-138258_Zlib.zip” project
2. Open the “Assets/Code/Libraries/SimpleZip/Demo” Scene
3. Enter Play Mode
4. Observe Game View or Console

Actual result: Exception “System.IO.FileNotFoundException: Could not load file or assembly ‘Ionic.Zlib.CF’" is thrown
Expected result: No exception is thrown

Reproducible with: 6000.4.0a2 (417aa67423b3), 6000.4.3f1, 6000.5.0b4, 6000.6.0a3
Not reproducible with: 6000.0.73f1, 6000.3.13f1, 6000.4.0a1

Reproducible on: macOS 26.3.1 (M1) (by user), Windows 11, Ubuntu 24.04.4 LTS
Not reproducible on: No other environment tested

Notes:

• Not reproducible in a build (neither Mono nor IL2CPP Scripting Backend)
• Changing the Scripting backend between the default Mono and IL2CPP doesn’t change outcome in Play Mode (the issue still reproduces)