Merge #19394

19394: tests/rmutex: Drop output dump from README.md r=maribu a=maribu

### Contribution description

We use test scripts to automatically classify the output of a test application as passing / failing. Users are not expected to manually compare the output with a dump of the output in a readme.

### Testing procedure

Doesn't apply

### Issues/PRs references

Fixes #19140

Fixes #19298

Co-authored-by: Marian Buschsieweke <marian.buschsieweke@ovgu.de>

tests/rmutex/README.md

@@ -7,80 +7,7 @@ should be able to lock (and unlock) the mutex first, followed by the
 other threads in the order of their priority (highest next). If two
 threads have the same priority the thread who comes first in the run queue
 (in this test this is the one with the lower thread id) should acquire the
-lock. The output should look like the following:
-
-```
-main(): This is RIOT! (Version: xxx)
-Recursive Mutex test
-Please refer to the README.md for more information
-
-Recursive Mutex test
-Please refer to the README.md for more information
-
-T3 (prio 6, depth 0): trying to lock rmutex now
-T4 (prio 4, depth 0): trying to lock rmutex now
-T5 (prio 5, depth 0): trying to lock rmutex now
-T6 (prio 2, depth 0): trying to lock rmutex now
-T7 (prio 3, depth 0): trying to lock rmutex now
-main: unlocking recursive mutex
-T6 (prio 2, depth 0): locked rmutex now
-T6 (prio 2, depth 1): trying to lock rmutex now
-T6 (prio 2, depth 1): locked rmutex now
-T6 (prio 2, depth 2): trying to lock rmutex now
-T6 (prio 2, depth 2): locked rmutex now
-T6 (prio 2, depth 3): trying to lock rmutex now
-T6 (prio 2, depth 3): locked rmutex now
-T6 (prio 2, depth 3): unlocked rmutex
-T6 (prio 2, depth 2): unlocked rmutex
-T6 (prio 2, depth 1): unlocked rmutex
-T6 (prio 2, depth 0): unlocked rmutex
-T7 (prio 3, depth 0): locked rmutex now
-T7 (prio 3, depth 1): trying to lock rmutex now
-T7 (prio 3, depth 1): locked rmutex now
-T7 (prio 3, depth 2): trying to lock rmutex now
-T7 (prio 3, depth 2): locked rmutex now
-T7 (prio 3, depth 3): trying to lock rmutex now
-T7 (prio 3, depth 3): locked rmutex now
-T7 (prio 3, depth 4): trying to lock rmutex now
-T7 (prio 3, depth 4): locked rmutex now
-T7 (prio 3, depth 4): unlocked rmutex
-T7 (prio 3, depth 3): unlocked rmutex
-T7 (prio 3, depth 2): unlocked rmutex
-T7 (prio 3, depth 1): unlocked rmutex
-T7 (prio 3, depth 0): unlocked rmutex
-T4 (prio 4, depth 0): locked rmutex now
-T4 (prio 4, depth 1): trying to lock rmutex now
-T4 (prio 4, depth 1): locked rmutex now
-T4 (prio 4, depth 2): trying to lock rmutex now
-T4 (prio 4, depth 2): locked rmutex now
-T4 (prio 4, depth 2): unlocked rmutex
-T4 (prio 4, depth 1): unlocked rmutex
-T4 (prio 4, depth 0): unlocked rmutex
-T5 (prio 5, depth 0): locked rmutex now
-T5 (prio 5, depth 1): trying to lock rmutex now
-T5 (prio 5, depth 1): locked rmutex now
-T5 (prio 5, depth 2): trying to lock rmutex now
-T5 (prio 5, depth 2): locked rmutex now
-T5 (prio 5, depth 2): unlocked rmutex
-T5 (prio 5, depth 1): unlocked rmutex
-T5 (prio 5, depth 0): unlocked rmutex
-T3 (prio 6, depth 0): locked rmutex now
-T3 (prio 6, depth 1): trying to lock rmutex now
-T3 (prio 6, depth 1): locked rmutex now
-T3 (prio 6, depth 2): trying to lock rmutex now
-T3 (prio 6, depth 2): locked rmutex now
-T3 (prio 6, depth 3): trying to lock rmutex now
-T3 (prio 6, depth 3): locked rmutex now
-T3 (prio 6, depth 4): trying to lock rmutex now
-T3 (prio 6, depth 4): locked rmutex now
-T3 (prio 6, depth 4): unlocked rmutex
-T3 (prio 6, depth 3): unlocked rmutex
-T3 (prio 6, depth 2): unlocked rmutex
-T3 (prio 6, depth 1): unlocked rmutex
-T3 (prio 6, depth 0): unlocked rmutex
-
-Test END, check the order of priorities above.
-```
+lock.
 
 Background
 ==========