Revert "github/zephyr.yml: use Zephyr docker-image v0.24.2"

This reverts commit e29572bb2d.

The Zephyr SDK 0.15.0 was exceptionally backwards-incompatible, which
meant the docker image could not have it ahead of time as usual, which
caused some CI failures. More details in
https://github.com/zephyrproject-rtos/zephyr/pull/49496

These CI failures were not a bug, they were a "feature": they drew our
attention to how unusual 0.15.0 was and they let us inform developers
before they hit the issue. Continuous Integration at its best; we want
more of that.

Before this unusual 0.15.0 event we had been using "latest" for many
months without any issue.

Signed-off-by: Marc Herbert <marc.herbert@intel.com>

.github/workflows/zephyr.yml

@@ -53,6 +53,6 @@ jobs:
       - name: build
         run: docker run -v "$(pwd)/workspace":/workspace
              --workdir /workspace
-             ghcr.io/zephyrproject-rtos/zephyr-build:v0.24.2
+             ghcr.io/zephyrproject-rtos/zephyr-build:latest
              ./sof/zephyr/docker-build.sh --cmake-args=-DEXTRA_CFLAGS=-Werror
              --cmake-args=--warn-uninitialized ${{ matrix.IPC_platforms }}