Running a armhf container for raspberry pi zero compiling

Hello I am currently trying to emulate a raspberry pi zero with this Dockerfile:

FROM python:3.7.3-stretch
ENV QEMU_CPU=arm1176 #ENV Var recognized in order to emulate armv6.
ENV QEMU_MACHINE=versatilepb #Seems like its not used but is needed to emulate armhf

ENV CFLAGS=" -marm -mfpu=vfp -mtune=arm1176jzf-s -mfloat-abi=softfp"

COPY sources.list /etc/apt/sources.list

RUN wget https://archive.raspbian.org/raspbian.public.key -O - | apt-key add -

COPY . .

RUN python setup.py bdist --cythonize

The buildx command docker buildx build --platform=linux/arm/v6 -t skast/armv6 . --load

Basically it should import raspbian sources into the container and install all armhf related gcc compilers needed to "natively" build my cython packages.
The problem I ran into is that it seems that the container started with the command docker run --rm -it --platform=linux/arm/v6 skast/armv6 is armel, because on apt update with the imported raspbian commands it gives me this errors.

The uname -a command gives:
Linux 258b4dd0b814 5.12.13-arch1-2 #1 SMP PREEMPT Fri, 25 Jun 2021 22:56:51 +0000 armv6l GNU/Linux

What I need is a container that is running with multiarch, which emulates a raspberry pi zero but is not "completely" a raspberry pi like https://github.com/lukechilds/dockerpi

Start with the Dockerfile and the docker buildx build --platform=linux/arm/v6 command, then compare the architecture reported by uname -a with the behavior of apt update using the imported Raspbian sources. Determine whether the requested armhf Raspberry Pi Zero container setup is supported and document the result or required configuration.