ci: use shared variables anchors

Part-of: <https://dev.funkwhale.audio/funkwhale/funkwhale/-/merge_requests/2282>

.gitlab-ci.yml

@@ -4,6 +4,13 @@ variables:
 
   PIP_CACHE_DIR: $CI_PROJECT_DIR/.cache/pip
 
+.shared_variables:
+  # Keep the git files permissions during job setup
+  keep_git_files_permissions: &keep_git_files_permissions
+    GIT_STRATEGY: clone
+    GIT_DEPTH: "5"
+    FF_DISABLE_UMASK_FOR_DOCKER_EXECUTOR: "true"
+
 workflow:
   rules:
     - if: $CI_PIPELINE_SOURCE == "merge_request_event"
@@ -315,10 +322,7 @@ build_front:
   stage: build
   image: node:18-alpine
   variables:
-    # Keep the git files attributes during job setup
-    GIT_STRATEGY: clone
-    GIT_DEPTH: "5"
-    FF_DISABLE_UMASK_FOR_DOCKER_EXECUTOR: "true"
+    <<: *keep_git_files_permissions
   before_script:
     - apk add --no-cache jq bash coreutils python3
     - cd front
@@ -342,10 +346,7 @@ build_api:
   stage: build
   image: bash
   variables:
-    # Keep the git files attributes during job setup
-    GIT_STRATEGY: clone
-    GIT_DEPTH: "5"
-    FF_DISABLE_UMASK_FOR_DOCKER_EXECUTOR: "true"
+    <<: *keep_git_files_permissions
   script:
     - rm -rf api/tests
     - >
@@ -385,6 +386,8 @@ deploy_documentation:
     matrix:
       - COMPONENT: ["api", "front"]
   variables:
+    <<: *keep_git_files_permissions
+
     IMAGE_NAME: funkwhale/$COMPONENT
     IMAGE: $IMAGE_NAME:$CI_COMMIT_REF_NAME
     IMAGE_LATEST: $IMAGE_NAME:latest
@@ -393,8 +396,6 @@ deploy_documentation:
     DOCKER_DRIVER: overlay2
     DOCKER_TLS_CERTDIR: ""
     BUILD_PLATFORMS: linux/amd64,linux/arm64,linux/arm/v7
-
-    FF_DISABLE_UMASK_FOR_DOCKER_EXECUTOR: "true"
   tags:
     - multiarch
   services: