chore: migrate .goreleaser config to use docker_v2

[spiffcs]

Description

Work in progress to migrate/refactor the docker builds to use new goreleaser features.
https://goreleaser.com/customization/dockers_v2/

I know this is in alpha so I can revert the use of v2 and just solve the debug root/non-root issue. It was just overloading in the old syntax to think about everything that was being built.

Here is a link to the feedback discussion for the new feature:
https://github.com/orgs/goreleaser/discussions/6005

IMPORTANT: debug has been changed from non-root -> root.

Dockerfile.debug

A new non-root image has been added. This is a subtle change and we should discuss this here.
The other option is to not change the user behavior, keep debug as is and add a debug-root.

This is awkward naming since it's the inverse of the other two images, but might be worth doing as it doesn't change existing behavior of the tagged images.

  ┌───────────────┬──────────────────────────┬───────────────────────────────────────┬────────────────────────────────────┐
  │     Entry     │        Dockerfile        │            Tags per image             │               Images               │
  ├───────────────┼──────────────────────────┼───────────────────────────────────────┼────────────────────────────────────┤
  │ production    │ Dockerfile               │ latest, {{.Tag}}                      │ anchore/syft, ghcr.io/anchore/syft │
  ├───────────────┼──────────────────────────┼───────────────────────────────────────┼────────────────────────────────────┤
  │ nonroot       │ Dockerfile.nonroot       │ nonroot, {{.Tag}}-nonroot             │ anchore/syft, ghcr.io/anchore/syft │
  ├───────────────┼──────────────────────────┼───────────────────────────────────────┼────────────────────────────────────┤
  │ debug         │ Dockerfile.debug         │ debug, {{.Tag}}-debug                 │ anchore/syft, ghcr.io/anchore/syft │
  ├───────────────┼──────────────────────────┼───────────────────────────────────────┼────────────────────────────────────┤
  │ debug-nonroot │ Dockerfile.debug-nonroot │ debug-nonroot, {{.Tag}}-debug-nonroot │ anchore/syft, ghcr.io/anchore/syft │
  └───────────────┴──────────────────────────┴───────────────────────────────────────┴────────────────────────────────────┘

Each entry builds for 4 platforms: linux/amd64, linux/arm64, linux/ppc64le, linux/s390x.
4 entries × 2 registries × 2 tags = 16 manifest tags, each backed by 4 platform-specific images (64 platform images total).

Type of change

• Chore (improve the developer experience, fix a test flake, etc, without changing the visible behavior of Syft)

Issue references

Fixes: #4113