Make the call stack entries not editable

src/citra_qt/debugger/callstack.ui

@@ -17,6 +17,9 @@
    <layout class="QVBoxLayout" name="verticalLayout">
     <item>
      <widget class="QTreeView" name="treeView">
+      <property name="editTriggers">
+       <set>QAbstractItemView::NoEditTriggers</set>
+      </property>
       <property name="alternatingRowColors">
        <bool>true</bool>
       </property>