PlayStation platform does not have `isatty()`

[objectx]

Describe the bug
PlayStation platform does not have isatty(), but current Catch2 try to use it. This triggers a compilation error.

Expected behavior
Successfully compile

Reproduction steps
Build with PlayStation SDK.

Platform information:

• Compiler+version: Clang-20 variant
• Catch version: devel branch

Additional context
The __FreeBSD__ is pre-defined by a supplied Clang. This enables the isatty() usage.