test asm_gemm in CI

[Qazalin]

on macbook takes 3 seconds, it'll run the smaller correctness tests using a UOp gemm.
Skipped tests are mainly for speed benchmarking.

~/code/tinygrad (run_asm) > PYTHONPATH=. python  test/testextra/test_asm_gemm.py
....sssssss
----------------------------------------------------------------------
Ran 11 tests in 3.016s

OK (skipped=7)
asm_gemm: 3 used, 1 not used