piv: Devices used by other processes cause an error

[robin-nitrokey]

If a smartcard that is currently used by another process is connected while executing a PIV command, the following error occurs:

  File "/nix/store/z5yf0wjqs9963nx3429j45cg8aiw7wvb-pynitrokey-0.6.0/lib/python3.11/site-packages/pynitrokey/cli/nk3/piv.py", line 650, in write_certificate
    device = PivApp()
             ^^^^^^^^
  File "/nix/store/z5yf0wjqs9963nx3429j45cg8aiw7wvb-pynitrokey-0.6.0/lib/python3.11/site-packages/pynitrokey/nk3/piv_app.py", line 62, in __init__
    connection.connect()
  File "/nix/store/xigxrdaayzlpkqrmcv31p2b6l6xjfywk-python3.11-pyscard-2.0.9/lib/python3.11/site-packages/smartcard/CardConnectionDecorator.py", line 54, in connect
    self.component.connect(protocol, mode, disposition)
  File "/nix/store/xigxrdaayzlpkqrmcv31p2b6l6xjfywk-python3.11-pyscard-2.0.9/lib/python3.11/site-packages/smartcard/pcsc/PCSCCardConnection.py", line 123, in connect
    raise CardConnectionException(
smartcard.Exceptions.CardConnectionException: Unable to connect with protocol: T0 or T1. Sharing violation.: Sharing violation. (0x8010000B)

Steps to reproduce:

1. Connect Nitrokey Pro
2. Use Nitrokey Pro with GnuPG/scdaemon
3. Connect Nitrokey 3
4. Try to use Nitrokey 3 with nitropy nk3 piv ...

Possible solutions:

• filter readers by Nitrokey 3 to avoid connecting to other devices
• skip devices that raise CardConnectionException when connecting