d/pcscd.runit: add runit supervision capability

Hi pcsc-lite maintainer!

Would you consider adding this support for running pcscd via the runit supervisor, please?

I have confirmed that this works nicely, starting upon installation of a test package. No new lintian output as triggered.

Example output:

$ sudo sv stop pcscd
ok: down: pcscd: 0s, normally up
$ ykman oath info
WARNING: PC/SC not available. Smart card (CCID) protocols will not function.
ERROR: Unable to list devices for connection
ERROR: Failed to connect to YubiKey.
$ sudo sv start pcscd
ok: run: pcscd: (pid 29356) 0s
$ ykman oath info
OATH version: 5.2.7
Password protection: disabled
$ sudo sv status pcscd
run: pcscd: (pid 29356) 12s; run: log: (pid 28382) 754s
$ cat /var/log/runit/pcscd/current
2024-12-16_21:56:42.17667 invoke-run: starting pcscd
2024-12-16_21:56:42.20203 00000000 ../src/ccid_usb.c:740:OpenUSBByName() Can't claim interface 3/21: LIBUSB_ERROR_BUSY
2024-12-16_21:56:42.20214 00000174 ../src/ifdhandler.c:139:CreateChannelByNameOrChannel() failed
2024-12-16_21:56:42.20214 00000001 ../src/readerfactory.c:1144:RFInitializeReader() Open Port 0x200000 Failed (usb:1050/0407:libudev:2:/dev/bus/usb/003/021)
2024-12-16_21:56:42.20215 00000001 ../src/readerfactory.c:371:RFAddReader() Yubico YubiKey OTP+FIDO+CCID init failed.
2024-12-16_21:56:42.20215 00000016 ../src/hotplug_libudev.c:517:HPAddDevice() Failed adding USB device: Yubico YubiKey OTP+FIDO+CCID
2024-12-16_22:08:22.90572 99999999 ../src/winscard.c:281:SCardConnect() Error Reader Exclusive
2024-12-16_22:08:56.29328 invoke-run: pcscd stopped
2024-12-16_22:09:04.58010 invoke-run: starting pcscd

I use this combination of software regularly enough that I would expect to spot future issues with this integration. I should also like to invite @Lorenzo.ru.g-guest to review if he wishes.

Thanks!

Andrew