SU2/TestCases/TestCase.py uses platform.processor() which returns i386 on an Intel Core i7 MacBookPro running mac OS 11.7. This just differentiates between Power PC vs Intel processors and not necessarily between 32-bit and 64-bit architectures. This causes all the tests in the test suite to be skipped even though the machine is 64-bit.

platform.machine() returns x86_64 allowing the tests to run from the TestCase.py script.

Python documentation (3.12.0) also notes that many platforms do not provide the information for platform.processor() or simply return the same value as for platform.machine().

Suggestion is to replace platform.processor() with platform.machine().