Revert concurrency throttling for CI

Author: kateinoigakukun

extensions/cxx_debugging/tools/bootstrap.py

@@ -190,9 +190,6 @@ def stage2(source_dir, stage1_dir, OPTIONS):
     maybe_cmake(binary_dir, cmake_args, OPTIONS.verbose)
 
     num_cores = os.cpu_count()
-    # HACK: throttle the number of cores to avoid OOM on the CI
-    if os.getenv('CI'):
-        num_cores = min(num_cores, 1)
 
     env = os.environ.copy()