tests: benchmarks: multicore: idle_uarte: fix coverage after rework

Fix missing message in coverage mode.

Signed-off-by: Piotr Kosycarz <[email protected]>

Author: nordic-piks

tests/benchmarks/multicore/idle_uarte/testcase.yaml

@@ -164,5 +164,4 @@ tests:
       type: multi_line
       ordered: true
       regex:
-        - ".*Coverage analysis enabled.*"
         - ".*Coverage analysis start.*"