workflow: Update sonarcloud docker version

Use v0.28.7.

Signed-off-by: Jorgen Kvalvaag <jorgen.kvalvaag@nordicsemi.no>

Author: jorgenmk

.github/workflows/sonarcloud.yml

@@ -18,7 +18,7 @@ jobs:
   build:
     name: Build and analyze
     runs-on: self-hosted
-    container: ghcr.io/zephyrproject-rtos/ci:v0.27.4
+    container: ghcr.io/zephyrproject-rtos/ci:v0.28.7
     env:
       BUILD_WRAPPER_OUT_DIR: build_wrapper_output_directory # Directory where build-wrapper output will be placed
       CMAKE_PREFIX_PATH: /opt/toolchains