Try to config a git cache

.gitlab-ci.yml

@@ -1,6 +1,26 @@
 image: docker:19.03.12
 
-job-build-docker-latest:
+stages:
+  - update
+  - build
+
+cache:
+  key: blender-source
+  paths:
+    - /opt/blender-git/blender  # Blender git repository source
+    - /opt/blender-git/lib      # Blender Subversion lib package
+  policy: pull
+
+update:
+  stage: update
+  cache:
+    key: blender-source
+  script:
+    - cd /opt/blender-git
+    - clone https://git.blender.org/blender.git
+    - svn checkout
+
+build:
   rules:
     - changes:
         - build.json