Detect dnf5 at startup via 'dnf --version' output and route to
version-specific parsers and command arguments.
Key changes:
- DNF struct caches v5 detection result
- New parse_dnf5.go with parsers for all dnf5 output formats
- stripPreamble() removes dnf5 repository loading noise
- Command arguments adjusted: --installed, --upgrades, --available
- CI matrix expanded with fedora:latest (dnf5) alongside fedora:39 (dnf4)
- Full backward compatibility with dnf4 preserved
Implements the dnf sub-package with Manager, VersionQuerier, Holder,
Cleaner, FileOwner, RepoManager, KeyManager, Grouper, and NameNormalizer
interfaces.
Implements the rpm sub-package with Manager, FileOwner, and
NameNormalizer interfaces.
Both follow the existing pattern: exported methods on struct delegate to
unexported functions, _linux.go for real implementations, _other.go with
build-tag stubs, embedded snack.Locker for mutating operations, and
compile-time interface checks.
Includes parser tests for all output formats.
