auditd-config: increase line buffer size to 1024

[andre4ik3]

The current buffer size of 160 makes it hard to have lines e.g. with multiple paths in the Nix store for NixOS systems. Since each path has a prefix of 44 characters it becomes very easy to run into the 160 character limit, for example if you have an audisp-filter plugin with the filter rules also in the Nix store, the generated plugin config ends up as follows:

active = yes
args = allowlist /nix/store/xbvfkdgpga9v3fiybjjq7zzhcdyldm3r-audisp-filter.conf /nix/store/8xqp548q4a2gqyf5xkmv5023blyd3wxz-audit-4.1.2-unstable-2025-09-06-bin/bin/audisp-syslog LOG_USER LOG_INFO interpret
direction = out
format = string
path = /nix/store/8xqp548q4a2gqyf5xkmv5023blyd3wxz-audit-4.1.2-unstable-2025-09-06-bin/bin/audisp-filter
type = always

The second line ends up being over 200 characters long which runs over the 160 line limit. This PR bumps it to 1024 in a few places, like it is already in the plugin config parsing.