Apply migration script

Signed-off-by: Leandro Lucarella <luca-frequenz@llucax.com>

Author: llucax

.github/containers/nox-cross-arch/arm64-ubuntu-20.04-python-3.11.Dockerfile

@@ -261,30 +261,3 @@ These are the steps to create a new release:
    should be automated eventually too).
 
 7. Celebrate!
-
-##  Cross-Arch Testing
-
-This project has built-in support for testing across multiple architectures.
-Currently, our CI conducts tests on `arm64` machines using QEMU emulation. We
-also have the flexibility to expand this support to include additional
-architectures in the future.
-
-This project contains Dockerfiles that can be used in the CI to test the
-python package in non-native machine architectures, e.g., `arm64`. The
-Dockerfiles exist in the directory `.github/containers/nox-cross-arch`, and
-follow a naming scheme so that they can be easily used in build matrices in the
-CI, in `nox-cross-arch` job. The naming scheme is:
-
-```
-<arch>-<os>-python-<python-version>.Dockerfile
-```
-
-E.g.,
-
-```
-arm64-ubuntu-20.04-python-3.11.Dockerfile
-```
-
-If a Dockerfile for your desired target architecture, OS, and python version
-does not exist here, please add one before proceeding to add your options to
-the test matrix.