ci: Pull Docker images from GitHub Container Registry

This commit updates the CI workflow to pull the Docker images from the
GitHub Container Registry (GHCR) to work around the pull rate limits of
the DockerHub.

Signed-off-by: Stephanos Ioannidis <[email protected]>

Author: stephanosio

.github/workflows/ci.yml

@@ -179,7 +179,7 @@ jobs:
           MATRIX_HOSTS+='{
               "name": "linux-x86_64",
               "runner": "zephyr_runner",
-              "container": "zephyrprojectrtos/sdk-build:v1.2.0",
+              "container": "ghcr.io/zephyrproject-rtos/sdk-build:v1.2.1",
               "archive": "tar.gz"
             },'
         fi
@@ -188,7 +188,7 @@ jobs:
           MATRIX_HOSTS+='{
               "name": "linux-aarch64",
               "runner": "zephyr_runner",
-              "container": "zephyrprojectrtos/sdk-build:v1.2.0",
+              "container": "ghcr.io/zephyrproject-rtos/sdk-build:v1.2.1",
               "archive": "tar.gz"
             },'
         fi
@@ -215,7 +215,7 @@ jobs:
           MATRIX_HOSTS+='{
               "name": "windows-x86_64",
               "runner": "zephyr_runner",
-              "container": "zephyrprojectrtos/sdk-build:v1.2.0",
+              "container": "ghcr.io/zephyrproject-rtos/sdk-build:v1.2.1",
               "archive": "zip"
             },'
         fi