ci: Fix macOS-cross SDK rsync

This should fix the macOS-cross build on Cirrus CI containers.

Locally this was already working, because the SDK was cached in
/ci_container_base/ in the image, which is also the folder used for a
later CI run.

However, on Cirrus CI, when using an image *and* a custom BASE_ROOT_DIR,
the SDK will not be found in /ci_base_install/, nor in BASE_ROOT_DIR.

Fix this by normalizing *all* folders to /ci_container_base/.

ci/test_imagefile

@@ -11,6 +11,6 @@ ARG FILE_ENV
 ENV FILE_ENV=${FILE_ENV}
 
 COPY ./ci/retry/retry /usr/bin/retry
-COPY ./ci/test/00_setup_env.sh ./${FILE_ENV} ./ci/test/01_base_install.sh /ci_base_install/ci/test/
+COPY ./ci/test/00_setup_env.sh ./${FILE_ENV} ./ci/test/01_base_install.sh /ci_container_base/ci/test/
 
-RUN ["bash", "-c", "cd /ci_base_install/ && set -o errexit && source ./ci/test/00_setup_env.sh && ./ci/test/01_base_install.sh"]
+RUN ["bash", "-c", "cd /ci_container_base/ && set -o errexit && source ./ci/test/00_setup_env.sh && ./ci/test/01_base_install.sh"]