Fix Traefik version detection across architectures

[ychampion]

Summary

Fix Traefik binary version detection for release builds whose version data is not NUL-prefixed.

Motivation

Recent amd64, arm/v6, ppc64le, and s390x binaries are missed or can be reported as a dependency version such as 2.7.0. Closes #4980.

Changes

• Prefer version data terminated by multiple NUL bytes, then fall back to legacy layouts.
• Add digest-pinned release fixtures for four affected architectures.
• Cover the s390x dependency-version ordering regression.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change
• Documentation
• Chore
• Performance

Validation

• go test ./syft/pkg/cataloger/binary -run '^Test_Cataloger_PositiveCases$/^traefik/' -count=1
• go test ./syft/pkg/cataloger/binary -run '^TestTraefikClassifierPrefersVersionData$' -count=1
• go test ./syft/pkg/cataloger/binary/internal/manager/... -count=1
• go vet ./syft/pkg/cataloger/binary ./syft/pkg/cataloger/binary/internal/manager/...
• Complete release binaries passed with -must-use-original-binaries for amd64 2.11.30, arm/v6 3.6.6, ppc64le 2.11.10, and s390x 2.10.5.
• The unrelated Docker-backed Java/ELF/PE package suite was not completed locally because its image fixtures exceeded available disk.

Checklist

• I have added unit tests that cover changed behavior
• I have tested my code in common scenarios and confirmed there are no regressions
• I have added comments to hard-to-understand sections