Feature: add Zlib license

[jcubic]

Before You Begin

Before proceeding, please make sure to follow these steps:

• I have checked for similar issues in the project's issue tracker.
• I have searched closed issues to see if a similar problem was reported
  before.

Issue Details

Tool doesn't recognize Zlib license:

2026-04-30 01:34:53.229 | WARNING | licensecheck.license_matrix:licenseLookup:114 - 'ZLIB' License not identified so falling back to UNKNOWN

System Information

Please provide the following additional information about your system or
environment:

• Operating System (OS): Fedora
• OS Version: 43
• Browser (if applicable):
• Browser Version (if applicable):
• Project Version (if applicable): 2025.1.0

Additional notes

It's more like a missing feature