Rename codesize expectation files. NFC (#25393)

This matches the `run_codesize_test` test helper.

Author: sbc100

test/codesize/audio_worklet_wasm.js renamed to test/codesize/audio_worklet_wasm.expected.js

@@ -124,7 +124,7 @@ def test_minimal_runtime_code_size(self, test_name, wasm2js, compare_js_output=F
     # Note that we do not compare the full wasm output since that is
     # even more fragile and can change with LLVM updates.
     if compare_js_output:
-      js_out = test_file('codesize', test_name + '.js')
+      js_out = test_file('codesize', test_name + '.expected.js')
       terser = shared.get_npm_cmd('terser')
       # N.b. this requires node in PATH, it does not run against NODE from
       # Emscripten config file. If you have this line fail, make sure 'node' is