ci: remove 'cambridge-lab' tag from RB3gen2 LAVA jobs

There are more RB3gen2 devices available in other locations now. The
"cambridge-lab" tag limited the jobs to only ones available in
Cambridge. This patch removes this limitation.

Signed-off-by: Milosz Wasilewski <[email protected]>

Author: mwasilew

ci/lava/qcs6490-rb3gen2-core-kit/boot.yaml

@@ -57,8 +57,6 @@ job_name: boot test ({{DEVICE_TYPE}}) {{GITHUB_RUN_ID}}
 metadata:
   build-commit: '{{GITHUB_SHA}}'
 priority: 50
-tags:
-- cambridge-lab
 timeouts:
   job:
     minutes: 15