Stereoscope pulls different images when using docker: vs registry: from multi-platform images

[Hritik14]

What happened:
On an arm machine, stereoscope produces different results when pulling a multi-platform image using docker scheme vs registry scheme.
The docker scheme correctly infers the host architecture and pulls the correct matching image whereas the registry scheme pulls only amd64/linux image when platform is not explicitly provided.

What you expected to happen:
The platform for both images should be the same, preferably the host platform.
If inference of platform is not intended in an OCI/registry source, this difference should be verbose in debug logs or in documentation.

How to reproduce it (as minimally and precisely as possible):
On an arm machine, registry scheme yields an x86 image (incorrectly)

; go run examples/basic.go registry:rust:1.42-slim-buster | grep binutils-x86
[0000] DEBUG image: source=OciRegistry location=rust:1.42-slim-buster
[0000] DEBUG pulling image info directly from registry image="rust:1.42-slim-buster"
[0000] DEBUG no registry credentials configured, using the default keychain
[0003] DEBUG image metadata: digest=sha256:165a37f9b454c1b000732bc6fb31edb6710818f6096796e7951a1e91cafa758d mediaType=application/vnd.docker.distribution.manifest.v2+json tags=[]
[0003] DEBUG layer metadata: index=0 digest=sha256:b60e5c3bcef2f42ec42648b3acf7baf6de1fa780ca16d9180f3b4a3f266fe7bc mediaType=application/vnd.docker.image.rootfs.diff.tar.gzip
[0005] DEBUG layer metadata: index=1 digest=sha256:508d8706fc1db20449e5e0fe22c65e1cce8ee30d062c5357f7e81f22cb8c3441 mediaType=application/vnd.docker.image.rootfs.diff.tar.gzip
 ...
    /usr/share/doc/binutils-x86-64-linux-gnu
 ...

On the same machine, docker scheme yields an arm image (correctly)

; go run examples/basic.go docker:rust:1.42-slim-buster | grep binutils-aarch64
[0000] DEBUG image: source=DockerDaemon location=rust:1.42-slim-buster
[0008] DEBUG image metadata: digest=sha256:8dc750c34fb3e46a4585e531416d995592fd7ca89630be76cca23ce1da26391f mediaType=application/vnd.docker.distribution.manifest.v2+json tags=[rust:1.42-slim-buster]
[0008] DEBUG layer metadata: index=0 digest=sha256:67d3a85d42a2b4ae3ca54ff7b6225bb136fbe0fa5732d9c5143470f13470bbde mediaType=application/vnd.docker.image.rootfs.diff.tar.gzip
[0008] DEBUG layer metadata: index=1 digest=sha256:081726014efb2e4d440405aee79d2cca3966c3fc965ce2cee13fd972c907e953 mediaType=application/vnd.docker.image.rootfs.diff.tar.gzip
    /usr/share/doc/binutils-aarch64-linux-gnu
...

Anything else we need to know?:
DaemonImageProvider infers host platform and pulls the correct image whereas
RegistryImageProvider uses go-containerregistry which defaults to amd64/linux when platform is missing rather than inferring the host platform.
See also:

• ggcr: No warning / documenation present for when platform defaults to amd64/linux google/go-containerregistry#1505

Environment:

• OS: MacOS Monterey, M1 Pro.