TEST: run less test in parallel (OOM)

Author: jordi-midokura

.github/workflows/test.yml

@@ -98,7 +98,7 @@ jobs:
           ASAN_OPTIONS: detect_leaks=1:detect_stack_use_after_return=1
           UBSAN_OPTIONS: print_stacktrace=1
           TERM: xterm
-        run: . .venv/bin/activate && make -C test -j RUNFLAGS='-c -t 60'
+        run: . .venv/bin/activate && make -C test -j50 RUNFLAGS='-c -t 60'
 
       - name: Print failure logs
         if: failure()