Revert "ci: disable Collabora's LAVA lab for maintance"

This reverts commit 3964a77454.

Signed-off-by: David Heidelberg <david.heidelberg@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20128>

.gitlab-ci.yml

@@ -18,7 +18,7 @@ variables:
   # Individual CI farm status, set to "offline" to disable jobs
   # running on a particular CI farm (ie. for outages, etc):
   FD_FARM: "online"
-  COLLABORA_FARM: "offline"
+  COLLABORA_FARM: "online"
   MICROSOFT_FARM: "online"
   LIMA_FARM: "online"
   IGALIA_FARM: "online"