CAMT v08 support

[devurandom]

Python fints older than 5.0.0 beta 1 did not support CAMT v08 transaction formats (raphaelm/python-fints#193, raphaelm/python-fints#200). German banks stopped supporting MT940 transaction formats 5 days ago (see also the headline on https://vrkennung.de/) and switched to CAMT version 08. The error message is:

Traceback (most recent call last):
  File "/tmp/fints2ledger249114-0.py", line 74, in <module>
    main()
    ~~~~^^
  File "/tmp/fints2ledger249114-0.py", line 55, in main
    transactions = retrieve_transactions(
        account=args["account"],
    ...<5 lines>...
        end=date_string_to_mt940_date(args["end"]),
    )
  File "/tmp/fints2ledger249114-0.py", line 10, in retrieve_transactions
    return TRetriever(client, selected_account).get_hbci_transactions(start, end)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^
  File "/tmp/fints2ledger249114-0.py", line 23, in get_hbci_transactions
    return self.client.get_transactions(account, start_date, end_date)
           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/nix/store/1vdmq901dlq8pjdj3ipl596ssv51pnn0-python3-3.13.9-env/lib/python3.13/site-packages/fints/client.py", line 533, in get_transactions
    hkkaz = self._find_highest_supported_command(HKKAZ5, HKKAZ6, HKKAZ7)
  File "/nix/store/1vdmq901dlq8pjdj3ipl596ssv51pnn0-python3-3.13.9-env/lib/python3.13/site-packages/fints/client.py", line 509, in _find_highest_supported_command
    raise FinTSUnsupportedOperation('No supported {} version found. I support {}, bank supports {}.'.format(
    ...<3 lines>...
    ))
fints.exceptions.FinTSUnsupportedOperation: No supported HIKAZS version found. I support (5, 6, 7), bank supports ().

fints2ledger: PyFintsError "Failed to get FinTS transactions, check the message above."
HasCallStack backtrace:
  bracket, called at ./System/IO/Temp.hs:100:3 in temporary-1.3-6WiaQjQVBun5gScuWzOxpE:System.IO.Temp

fints2ledger will have to update fints (

fints2ledger/requirements.txt

Line 1 in 4b11041

fints>=4,<5

) and nixpkgs will have to provide fints v5 (https://github.com/NixOS/nixpkgs/blob/9bb748c6584f1489567f0e45a963438ff22da2b3/pkgs/development/python-modules/fints/default.nix#L16).

See-also: #40
See-also: NixOS/nixpkgs#466577
See-also: NixOS/nixpkgs#478074