Update Docker Compose Apple Silicon guidance

The AtoM development service images now publish ARM64 variants, so Apple
Silicon and other ARM-based hosts can use the default Compose file without
an additional platform override.

Discourage `platform: linux/amd64` for everyday ARM development because it
forces emulation instead of using native ARM64 images.

Image variant checks:

  docker buildx imagetools inspect docker.elastic.co/elasticsearch/elasticsearch-oss:7.10.2
  docker buildx imagetools inspect percona/percona-server:8.4

Author: sevein

dev-manual/env/compose.rst

@@ -74,26 +74,20 @@ don't want to do so each time we invoke the ``docker compose`` command.
    # For fish users
    set -lx COMPOSE_FILE (pwd)/docker/docker-compose.dev.yml
 
-ARM-based machines
-------------------
-
-If you are using an ARM-based machine such as Apple Silicon MacBooks, you will need to use
-an additional override file that is provided to ensure compatibility. The Elasticsearch and Percona
-images need to run with platform emulation since they don't support ARM64 natively.
-
-For ARM-based machines, set the ``COMPOSE_FILE`` environment variable to include
-both the development file and the ARM override file:
-
-.. code-block:: bash
-
-   # For bash users (most of you)
-   export COMPOSE_FILE="$PWD/docker/docker-compose.dev.yml:$PWD/docker/docker-compose.override.arm.yml"
-
-   # For fish users
-   set -lx COMPOSE_FILE (pwd)/docker/docker-compose.dev.yml:(pwd)/docker/docker-compose.override.arm.yml
-
-This override file forces Docker to use platform emulation to run the Elasticsearch and Percona containers 
-with ``linux/amd64`` architecture on ARM-based machines.
+Apple Silicon and other ARM-based machines
+------------------------------------------
+
+Docker automatically selects the native image variant for your Docker engine
+when an image publishes a multi-architecture manifest. The development service
+images used by AtoM, including Elasticsearch and Percona, now publish ARM64
+variants, so the default Compose file can run those services natively on Apple
+Silicon.
+
+Platform emulation is only needed if a service is explicitly configured with
+``platform: linux/amd64``. We discourage that for everyday development on
+ARM-based machines because it forces the affected container to run through
+emulation instead of using the native ARM64 image, which is generally slower and
+more resource-intensive.
 
 Running the containers
 ======================