Remove unused theme constants in Tab(Container)

doc/classes/TabContainer.xml

@@ -204,10 +204,6 @@
 		</theme_item>
 		<theme_item name="increment_highlight" type="Texture2D">
 		</theme_item>
-		<theme_item name="label_valign_bg" type="int" default="2">
-		</theme_item>
-		<theme_item name="label_valign_fg" type="int" default="0">
-		</theme_item>
 		<theme_item name="menu" type="Texture2D">
 		</theme_item>
 		<theme_item name="menu_highlight" type="Texture2D">
@@ -222,7 +218,5 @@
 		</theme_item>
 		<theme_item name="tab_fg" type="StyleBox">
 		</theme_item>
-		<theme_item name="top_margin" type="int" default="24">
-		</theme_item>
 	</theme_items>
 </class>

doc/classes/Tabs.xml

@@ -285,10 +285,6 @@
 		</theme_item>
 		<theme_item name="increment_highlight" type="Texture2D">
 		</theme_item>
-		<theme_item name="label_valign_bg" type="int" default="2">
-		</theme_item>
-		<theme_item name="label_valign_fg" type="int" default="0">
-		</theme_item>
 		<theme_item name="panel" type="StyleBox">
 		</theme_item>
 		<theme_item name="tab_bg" type="StyleBox">
@@ -297,7 +293,5 @@
 		</theme_item>
 		<theme_item name="tab_fg" type="StyleBox">
 		</theme_item>
-		<theme_item name="top_margin" type="int" default="24">
-		</theme_item>
 	</theme_items>
 </class>

scene/resources/default_theme/default_theme.cpp

@@ -706,9 +706,6 @@ void fill_default_theme(Ref<Theme> &theme, const Ref<Font> &default_font, const
 	theme->set_color("font_color_disabled", "TabContainer", control_font_color_disabled);
 
 	theme->set_constant("side_margin", "TabContainer", 8 * scale);
-	theme->set_constant("top_margin", "TabContainer", 24 * scale);
-	theme->set_constant("label_valign_fg", "TabContainer", 0 * scale);
-	theme->set_constant("label_valign_bg", "TabContainer", 2 * scale);
 	theme->set_constant("hseparation", "TabContainer", 4 * scale);
 
 	// Tabs
@@ -732,9 +729,6 @@ void fill_default_theme(Ref<Theme> &theme, const Ref<Font> &default_font, const
 	theme->set_color("font_color_bg", "Tabs", control_font_color_low);
 	theme->set_color("font_color_disabled", "Tabs", control_font_color_disabled);
 
-	theme->set_constant("top_margin", "Tabs", 24 * scale);
-	theme->set_constant("label_valign_fg", "Tabs", 0 * scale);
-	theme->set_constant("label_valign_bg", "Tabs", 2 * scale);
 	theme->set_constant("hseparation", "Tabs", 4 * scale);
 
 	// Separators