## Problem
Currently, even if `LAMBDA_REMOTE_DOCKER=1`, we unzip the zip files in the directory they are in, which is usually /var/lib/localstack, which usually has a bind mount to the host.
On docker desktop, due to the use of grpc-FUSE (on macos), this can be very slow, about 200 times slower than on volumes / directly on the host. With experimental virtio filesystem enabled (also on macos), this can be reduced to about 30 times as slow, but still problematic.
This means a lambda may take a lot of time processing, for each additional layer some more. This especially affects nodejs lambdas with huge node_modules folders.

## Probable solution
At least if `LAMBDA_REMOTE_DOCKER=1`, we should leave the initial zip files on the bind mount (for persistence etc), but the working directories after unzipping should be located on non-bind mounts, to speed up the IO for unzipping.
return importlib.machinery.SourceFileLoader(name, file).load_module()
def exec_lambda_code(script, handler_function="handler", lambda_cwd=None, lambda_env=None):
    
    
    def _do_exec_lambda_code():
        if lambda_cwd or lambda_env:
            if lambda_cwd:
                previous_cwd = os.getcwd()
                os.chdir(lambda_cwd)
                sys.path = [lambda_cwd] + sys.path
            if lambda_env:
                previous_env = dict(os.environ)
                os.environ.update(lambda_env)
        
        lambda_id = "l_%s" % short_uid()
        lambda_file = LAMBDA_SCRIPT_PATTERN.replace("*", lambda_id)
        save_file(lambda_file, script)
        
        TMP_FILES.append(lambda_file)
        TMP_FILES.append("%sc" % lambda_file)
        try:
            pre_sys_modules_keys = set(sys.modules.keys())