test(e2e): close the Telex word before Return

Telex commits on a word boundary, not on Return, so the final syllable was
still composing when Return fired and committed into the following line.
No two repetitions agreed. The other three engines commit on Return.

Co-authored-by: Orca <help@stably.ai>

tests/e2e/terminal-ibus-engine-input-profiles.ts

@@ -119,9 +119,13 @@ export const nativeIbusEngineInputProfiles: Record<string, NativeIbusEngineInput
     scenarios: [
       {
         title: 'commits Telex diacritics without leaked keystroke Latin',
-        expectedText: 'tiếng việt',
+        expectedText: 'tiếng việt ',
+        // Telex closes a word on a boundary, not on Return: hangul, anthy and libpinyin
+        // all commit their preedit when Return arrives, and this engine does not. Without
+        // the trailing space the final syllable is still composing when Return fires, so
+        // it commits into the *next* line and no two repetitions agree.
         drive: ({ key, typeClearingModifiers }) => {
-          typeClearingModifiers('tieengs vieejt')
+          typeClearingModifiers('tieengs vieejt ')
           key('Return')
         }
       }