This is unnecessary and was a mistake to include. (#2496)

Signed-off-by: Adam Treat <treat.adam@gmail.com>

gpt4all-chat/chatviewtextprocessor.cpp

@@ -899,8 +899,6 @@ void ChatViewTextProcessor::handleTextChanged()
     QTextCursor cursor(doc);
     QString invisibleCharacter = QString(QChar(0xFEFF));
     cursor.insertText(invisibleCharacter, QTextCharFormat());
-
-    m_syntaxHighlighter->rehighlight();
     m_isProcessingText = false;
 }