chore: updating cryptography to 3.4.8

[k9ert]

(.env) ➜  tools git:(kn/update_cryptography) ✗ pytest                                    
========================================= test session starts ==========================================
platform darwin -- Python 3.9.23, pytest-7.2.0, pluggy-0.13.1
rootdir: /Users/kim/pubsrc/specter-bootloader/tools, configfile: pytest.ini
plugins: cov-2.10.0
collected 42 items                                                                                     

bech32/segwit_addr_test.py .....                                                                 [ 11%]
core/blsection_test.py ...........................                                               [ 76%]
core/integritychk_test.py .                                                                      [ 78%]
core/memmap_test.py .                                                                            [ 80%]
core/recovery_test.py .                                                                          [ 83%]
core/signature_test.py .......                                                                   [100%]

========================================== 42 passed in 0.60s ==========================================
(.env) ➜  tools git:(kn/update_cryptography) ✗