UI/Qt: Remove the built-in Inspector widget

Author: https://github.com/trflynn89
Commit: 1c696e7893
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/3956

UI/Qt/Tab.h

@@ -24,7 +24,6 @@
 namespace Ladybird {
 
 class BrowserWindow;
-class InspectorWidget;
 
 class HyperlinkLabel final : public QLabel {
     Q_OBJECT
@@ -66,12 +65,6 @@ public:
     void open_file();
     void update_reset_zoom_button();
 
-    enum class InspectorTarget {
-        Document,
-        HoveredElement
-    };
-    void show_inspector_window(InspectorTarget = InspectorTarget::Document);
-
     void show_find_in_page();
     void find_previous();
     void find_next();
@@ -124,10 +117,6 @@ private:
     void open_link_in_new_tab(URL::URL const&);
     void copy_link_url(URL::URL const&);
 
-    void close_sub_widgets();
-
-    void recreate_inspector();
-
     QBoxLayout* m_layout { nullptr };
     QToolBar* m_toolbar { nullptr };
     QToolButton* m_hamburger_button { nullptr };
@@ -172,8 +161,6 @@ private:
 
     int tab_index();
 
-    Ladybird::InspectorWidget* m_inspector_widget { nullptr };
-
     QPointer<QDialog> m_dialog;
 
     bool m_can_navigate_back { false };