MAINT: update documentation only in main

.gitlab-ci.yml

@@ -68,11 +68,12 @@ test:
 
 # Build the sphinx documentation and make it ready for deployment by Gitlab Pages
 # Special job for serving a static website. See https://docs.gitlab.com/ee/ci/yaml/README.html#pages
-pages:
-  tags: [ docker ]
+pages_prepare: &pages_prepare
+  tags: [ cached-dind ]
   stage: deploy
   only:
-    - web
+    refs:
+      - /^release-.*$/i
   script:
     - mkdir -p build
     - cd build
@@ -82,3 +83,8 @@ pages:
   artifacts:
     paths:
       - public
+pages:
+  <<: *pages_prepare
+  only:
+    refs:
+      - main