[Wasm] Disable os_stdlib tests for WASI due to no dynamic loading

Author: kateinoigakukun

test/lit.cfg

@@ -2137,7 +2137,7 @@ if run_vendor != 'apple':
 
 if 'remote-run-host' in lit_config.params:
     configure_remote_run()
-elif not kIsWindows:
+elif not kIsWindows and not run_os == 'wasi':
     if 'use_os_stdlib' in lit_config.params:
         config.available_features.add('use_os_stdlib')