Try to fix flaky tests

.github/workflows/osrm-backend.yml

@@ -575,8 +575,12 @@ jobs:
 
         # All tests assume to be run from the build directory
         pushd ${OSRM_BUILD_DIR}
-        for i in $(seq 1 1000); do
-          ./unit_tests/library-tests
+        for i in $(seq 1 100); do
+            echo "Iteration $i"
+            for test in ./unit_tests/*-tests; do
+                echo "Running $test"
+                $test
+            done
         done
         if [ -z "${ENABLE_SANITIZER}" ]; then
           npm run nodejs-tests