disable building against coq.dev as upstream is currently broken

See https://github.com/coq/coq/issues/8003

.gitlab-ci.yml

@@ -26,11 +26,11 @@ variables:
 
 ## Build jobs
 
-build-coq.dev:
-  <<: *template
-  variables:
-    OPAM_PINS: "coq version dev"
-    VALIDATE: "1"
+#build-coq.dev:
+#  <<: *template
+#  variables:
+#    OPAM_PINS: "coq version dev"
+#    VALIDATE: "1"
 
 build-coq.8.8.dev:
   <<: *template