chat(build): fix broken installer on macOS (#2973)

Signed-off-by: Jared Van Bortel <jared@nomic.ai>

gpt4all-chat/qml/MyDirectoryField.qml

@@ -0,0 +1,20 @@
+import QtCore
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Controls.Basic
+import llm
+
+TextField {
+    id: myDirectoryField
+    padding: 10
+    property bool isValid: LLM.directoryExists(text)
+    color: text === "" || isValid ? theme.textColor : theme.textErrorColor
+    background: Rectangle {
+        implicitWidth: 150
+        color: theme.controlBackground
+        border.width: 1
+        border.color: theme.controlBorder
+        radius: 10
+    }
+    ToolTip.delay: Qt.styleHints.mousePressAndHoldInterval
+}