This commit re-enables the tests in the build process which are
currently commented out.
It is possible to build the tests using `-DWHISPER_BUILD_TESTS=ON` and
then run a single test using:
```console
$ ctest -R test-whisper-cli-tiny.en --test-dir build
Internal ctest changing into directory: /home/danbev/work/ai/whisper-work/build
Test project /home/danbev/work/ai/whisper-work/build
Start 2: test-whisper-cli-tiny.en
1/1 Test #2: test-whisper-cli-tiny.en ......... Passed 4.44 sec
100% tests passed, 0 tests failed out of 1
Label Time Summary:
en = 4.44 sec*proc (1 test)
gh = 4.44 sec*proc (1 test)
tiny = 4.44 sec*proc (1 test)
Total Test time (real) = 4.44 sec
```
Some of the tests take a long time to run so it might not be a good idea
to enable them in CI, or perhaps we could only run a subset of the tests
in CI.