fix test

Author: Will-ShaoHua

packages/amazonq/test/unit/codewhisperer/util/runtimeLanguageContext.test.ts

@@ -177,7 +177,6 @@ describe('runtimeLanguageContext', function () {
             'jsx',
             'kotlin',
             'php',
-            'plaintext',
             'python',
             'ruby',
             'rust',
@@ -288,7 +287,6 @@ describe('runtimeLanguageContext', function () {
             ['jsx', 'jsx'],
             ['kotlin', 'kt'],
             ['php', 'php'],
-            ['plaintext', 'txt'],
             ['python', 'py'],
             ['ruby', 'rb'],
             ['rust', 'rs'],