[buildbot] Bump to latest Buildbot release 3.5.0

[LEDE Commits]

ynezz pushed a commit to buildbot.git, branch master:
https://git.openwrt.org/33549d7cec20787751c0f4d2da4d3b38e9e919a6

commit 33549d7cec20787751c0f4d2da4d3b38e9e919a6
Author: Petr Štetiar <ynezz at true.cz>
AuthorDate: Fri Mar 25 22:38:54 2022 +0100

    Bump to latest Buildbot release 3.5.0
    
    Signed-off-by: Petr Štetiar <ynezz at true.cz>
---
 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 73d58f0..2ad470e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,5 +1,5 @@
 variables:
-  BUILDBOT_VERSION: 3.4.1
+  BUILDBOT_VERSION: 3.5.0
   OPENWRT_VERSION: $CI_COMMIT_SHORT_SHA
 
 include: