Docker images fail to build due to error in `debian:stable-slim`

The release of Debian 11 (buster) seems to have changed how APT repositories are addressed (see https://github.com/debuerreotype/docker-debian-artifacts/issues/134). Since the current debian:stable-slim image is still baseed on Debian 10 (bullseye), the following error happens when trying to build images based on it:

docker build -t gekkofs/docs:0.8.0 .
Sending build context to Docker daemon  3.584kB
Step 1/3 : FROM gekkofs/core:0.8.0
 ---> eb0ae9f9d621
Step 2/3 : LABEL Description="Debian-based environment suitable to build GekkoFS' documentation"
 ---> Using cache
 ---> 11afaab01511
Step 3/3 : RUN apt-get update &&     apt-get install -y --no-install-recommends 		python3 		python3-pip 		python3-dev 		python3-venv 		python3-setuptools 		doxygen 		graphviz &&     python3 -m pip install --upgrade pip &&     pip3 install sphinx sphinx_rtd_theme breathe &&     rm -rf /var/lib/apt/lists/* &&     apt-get clean && apt-get autoclean
 ---> Running in e3ac854d1b54
Ign:1 http://security.debian.org/debian-security stable/updates InRelease
Err:2 http://security.debian.org/debian-security stable/updates Release
  404  Not Found [IP: 151.101.2.132 80]
Get:3 http://deb.debian.org/debian stable InRelease [113 kB]
Get:4 http://deb.debian.org/debian stable-updates InRelease [36.8 kB]
Get:5 http://deb.debian.org/debian stable/main amd64 Packages [8178 kB]
Reading package lists...
E: The repository 'http://security.debian.org/debian-security stable/updates Release' does not have a Release file.
The command '/bin/sh -c apt-get update &&     apt-get install -y --no-install-recommends 		python3 		python3-pip 		python3-dev 		python3-venv 		python3-setuptools 		doxygen 		graphviz &&     python3 -m pip install --upgrade pip &&     pip3 install sphinx sphinx_rtd_theme breathe &&     rm -rf /var/lib/apt/lists/* &&     apt-get clean && apt-get autoclean' returned a non-zero code: 100
make: *** [Makefile:4: all] Error 100