gitlab-ci: Remove the Debian9-based containers and containers-layer3

According to our support policy, Debian 9 is not supported by the
QEMU project anymore. Since we now switched the MinGW cross-compiler
builds to Fedora, we do not need these Debian9-based containers
in the gitlab-CI anymore, and can now also get rid of the "layer3"
container build stage this way.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200921174320.46062-3-thuth@redhat.com>
Message-Id: <20200925154027.12672-11-alex.bennee@linaro.org>

.gitlab-ci.d/containers.yml

@@ -214,20 +214,6 @@ tricore-debian-cross-container:
   variables:
     NAME: debian-tricore-cross
 
-win32-debian-cross-container:
-  <<: *container_job_definition
-  stage: containers-layer3
-  needs: ['amd64-debian9-mxe-container']
-  variables:
-    NAME: debian-win32-cross
-
-win64-debian-cross-container:
-  <<: *container_job_definition
-  stage: containers-layer3
-  needs: ['amd64-debian9-mxe-container']
-  variables:
-    NAME: debian-win64-cross
-
 xtensa-debian-cross-container:
   <<: *container_job_definition
   variables:

.gitlab-ci.yml

@@ -4,7 +4,6 @@
 stages:
   - containers
   - containers-layer2
-  - containers-layer3
   - build
   - test