Mark test_itimer as flaky. NFC (emscripten-core#20126)

See emscripten-core#20125

test/test_other.py

@@ -34,7 +34,7 @@
 from common import create_file, parameterized, NON_ZERO, node_pthreads, TEST_ROOT, test_file
 from common import compiler_for, EMBUILDER, requires_v8, requires_node, requires_wasm64, requires_node_canary
 from common import requires_wasm_eh, crossplatform, with_both_sjlj, also_with_standalone_wasm
-from common import also_with_minimal_runtime, also_with_wasm_bigint, also_with_wasm64
+from common import also_with_minimal_runtime, also_with_wasm_bigint, also_with_wasm64, flaky
 from common import EMTEST_BUILD_VERBOSE, PYTHON
 from tools import shared, building, utils, response_file, cache
 from tools.utils import read_file, write_file, delete_file, read_binary
@@ -13255,6 +13255,7 @@ def test_signext_lowering(self):
     err = self.run_process(cmd + ['-sMIN_CHROME_VERSION=73'], stderr=subprocess.PIPE).stderr
     self.assertContained('--signext-lowering', err)
 
+  @flaky('https://github.com/emscripten-core/emscripten/issues/20125')
   def test_itimer(self):
     self.do_other_test('test_itimer.c')