ci-test: re-enable build simulation caching

In 438f1e2a we accidentally disabled
caching for the build simulation by moving the cache definition to a job
class. The order of inheritance led to the cache configuration being
overwritten by the one of the "buildbase" class. Change inheritance
order to fix this.

build-jobs-ci-test.yml.jinja2

@@ -120,8 +120,8 @@ build:check-foo-branch:
 
 simulate-build-seco-mx6:
   extends:
-    - .simulate_build
     - .buildbase
+    - .simulate_build
   variables:
     # We have to specify a tag here instead of getting the artifacts from a master
     # branch, because we don't always execute the full pipeline on the master branches.
@@ -131,8 +131,8 @@ simulate-build-seco-mx6:
 
 simulate-buildsdk-seco-mx6:
   extends:
-    - .simulate_build
     - .buildbase
+    - .simulate_build
   variables:
     BUILD_ARTIFACTS: https://git.seco.com/seco-ne/yocto/manifest/-/jobs/artifacts/kirkstone/7.0/download?job=buildsdk-seco-mx6
     ARTIFACTS_PATH: build-*/tmp/deploy/sdk/*