Update test code after #20067 was fixed. NFC (#25156)

This should have been part of #25073.

Author: sbc100

test/test_core.py

@@ -9677,7 +9677,6 @@ def test_abort_on_exceptions_main(self):
     self.assertNotContained('Aborted', output)
 
   @node_pthreads
-  @flaky('https://github.com/emscripten-core/emscripten/issues/20067')
   @no_esm_integration('ABORT_ON_WASM_EXCEPTIONS is not compatible with WASM_ESM_INTEGRATION')
   def test_abort_on_exceptions_pthreads(self):
     self.set_setting('ABORT_ON_WASM_EXCEPTIONS')
@@ -9690,7 +9689,6 @@ def test_abort_on_exceptions_pthreads(self):
   @no_esm_integration('ABORT_ON_WASM_EXCEPTIONS is not compatible with WASM_ESM_INTEGRATION')
   @is_slow_test
   def test_stress_proxy_to_pthread_hello_world(self):
-    self.skipTest('https://github.com/emscripten-core/emscripten/issues/20067')
     self.set_setting('ABORT_ON_WASM_EXCEPTIONS')
     self.set_setting('PROXY_TO_PTHREAD')
     self.set_setting('EXIT_RUNTIME')