[buildbot] ci: use private runner

[LEDE Commits]

ynezz pushed a commit to buildbot.git, branch master:
https://git.openwrt.org/4e9e74c07673e75554d30be162774f3bac32ac52

commit 4e9e74c07673e75554d30be162774f3bac32ac52
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Sat Mar 13 23:33:49 2021 +0100

    ci: use private runner
    
    Shared runners seems to be unreliable lately and private runner should
    be more secure as well.
    
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 .gitlab/docker.yml | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/.gitlab/docker.yml b/.gitlab/docker.yml
index 501519b..752cca9 100644
--- a/.gitlab/docker.yml
+++ b/.gitlab/docker.yml
@@ -1,6 +1,9 @@
 .docker in docker:
   tags:
-    - gce
+    - linux
+    - openwrt
+    - light-jobs
+    - docker-privileged
   image: docker:19.03.7
   services:
     - docker:19.03.7-dind