yuzu/configuration: Make slots private where applicable

These slots are only ever attached to event handling mechanisms within
the class itself, they're never used externally. Because of this, we can
make the functions private.

This also removes redundant usages of the private access specifier.

src/yuzu/configuration/configure_audio.h

@@ -21,10 +21,9 @@ public:
     void applyConfiguration();
     void retranslateUi();
 
-public slots:
+private:
     void updateAudioDevices(int sink_index);
 
-private:
     void setConfiguration();
     void setOutputSinkFromSinkID();
     void setAudioDeviceFromDeviceID();

src/yuzu/configuration/configure_debug.h

@@ -23,6 +23,5 @@ public:
 private:
     void setConfiguration();
 
-private:
     std::unique_ptr<Ui::ConfigureDebug> ui;
 };

src/yuzu/configuration/configure_dialog.h

@@ -25,6 +25,5 @@ public:
 private:
     void setConfiguration();
 
-private:
     std::unique_ptr<Ui::ConfigureDialog> ui;
 };

src/yuzu/configuration/configure_graphics.h

@@ -23,7 +23,6 @@ public:
 private:
     void setConfiguration();
 
-private:
     std::unique_ptr<Ui::ConfigureGraphics> ui;
     QColor bg_color;
 };

src/yuzu/configuration/configure_web.h

@@ -22,13 +22,12 @@ public:
     void applyConfiguration();
     void retranslateUi();
 
-public slots:
+private:
     void RefreshTelemetryID();
     void OnLoginChanged();
     void VerifyLogin();
     void OnLoginVerified();
 
-private:
     void setConfiguration();
 
     bool user_verified = true;