Remove dead unitframes showtooltip setting

The mouseover-scripts migration dropped the unit frame OnEnter/OnLeave
handlers that read C.unitframes[unit].showtooltip, so nothing consulted the
setting anymore. The engine mouseover (driven by the frame's unit attribute)
now shows the native tooltip unconditionally, so the option could not gate it
even if a reader remained.

Drop the config default, the "Enable Mouseover Tooltip" GUI checkbox, and the
now-orphaned locale string from all translation files.

env/translations_deDE.lua

@@ -290,7 +290,6 @@ pfUI_translation["deDE"] = {
   ["Enable Mana Ticks"] = nil,
   ["Enable Micro Bar"] = nil,
   ["Enable Mouselook With Right Click"] = nil,
-  ["Enable Mouseover Tooltip"] = nil,
   ["Enable Movable Bags"] = nil,
   ["Enable Offscreen Frame Positions"] = nil,
   ["Enable Overlap"] = nil,

env/translations_enUS.lua

@@ -293,7 +293,6 @@ pfUI_translation["enUS"] = {
   ["Enable Mana Ticks"] = nil,
   ["Enable Micro Bar"] = nil,
   ["Enable Mouselook With Right Click"] = nil,
-  ["Enable Mouseover Tooltip"] = nil,
   ["Enable Movable Bags"] = nil,
   ["Enable Offscreen Frame Positions"] = nil,
   ["Enable Overlap"] = nil,

env/translations_esES.lua

@@ -290,7 +290,6 @@ pfUI_translation["esES"] = {
   ["Enable Mana Ticks"] = "Activar el indicador de pulsos del maná",
   ["Enable Micro Bar"] = "Activar microbarra",
   ["Enable Mouselook With Right Click"] = "Mirar usando el puntero con clic derecho",
-  ["Enable Mouseover Tooltip"] = "Activar la descripción emergente al pasar el puntero",
   ["Enable Movable Bags"] = "Permitir mover las bolsas",
   ["Enable Offscreen Frame Positions"] = "Permitir mover los marcos fuera de la pantalla",
   ["Enable Overlap"] = "Permitir superposición",

env/translations_frFR.lua

@@ -290,7 +290,6 @@ pfUI_translation["frFR"] = {
   ["Enable Mana Ticks"] = "Activer les Ticks de mana",
   ["Enable Micro Bar"] = "Activer la barre des menus miniature",
   ["Enable Mouselook With Right Click"] = "Activer le déplacement de la caméra avec le clic droit",
-  ["Enable Mouseover Tooltip"] = "Activer l'infobulle au passage de la souris",
   ["Enable Movable Bags"] = "Activer les sacs mobiles",
   ["Enable Offscreen Frame Positions"] = "Activer le positionnement des cadres en dehors de l'écran",
   ["Enable Overlap"] = "Activer la superposition",

env/translations_koKR.lua

@@ -290,7 +290,6 @@ pfUI_translation["koKR"] = {
   ["Enable Mana Ticks"] = nil,
   ["Enable Micro Bar"] = "미니바 보기(블리자드 마이크로바)",
   ["Enable Mouselook With Right Click"] = "오른쪽 클릭 Mouselook 사용",
-  ["Enable Mouseover Tooltip"] = nil,
   ["Enable Movable Bags"] = nil,
   ["Enable Offscreen Frame Positions"] = "오프스크린 프레임 위치 활성화",
   ["Enable Overlap"] = "겹쳐서 표시",

env/translations_ruRU.lua

@@ -290,7 +290,6 @@ pfUI_translation["ruRU"] = {
   ["Enable Mana Ticks"] = "Включить восполнение маны",
   ["Enable Micro Bar"] = "Включить панель микро меню",
   ["Enable Mouselook With Right Click"] = "Включить нажатие правой кнопки мыши на индикаторе здоровья",
-  ["Enable Mouseover Tooltip"] = "Включить подсказку при наведении мыши",
   ["Enable Movable Bags"] = "Включить подвижные сумки",
   ["Enable Offscreen Frame Positions"] = "Включить расположение окон за пределами экрана",
   ["Enable Overlap"] = "Включить перекрытие",

env/translations_zhCN.lua

@@ -290,7 +290,6 @@ pfUI_translation["zhCN"] = {
   ["Enable Mana Ticks"] = "显示法力值刻度",
   ["Enable Micro Bar"] = "显示菜单栏",
   ["Enable Mouselook With Right Click"] = "启动右键移动镜头",
-  ["Enable Mouseover Tooltip"] = "启用鼠标悬停工具提示",
   ["Enable Movable Bags"] = "启用可移动包裹",
   ["Enable Offscreen Frame Positions"] = "允许本插件所有框体移出屏幕边缘",
   ["Enable Overlap"] = "叠加显示",

env/translations_zhTW.lua

@@ -290,7 +290,6 @@ pfUI_translation["zhTW"] = {
   ["Enable Mana Ticks"] = nil,
   ["Enable Micro Bar"] = "顯示功能表列",
   ["Enable Mouselook With Right Click"] = "啟動右鍵移動鏡頭",
-  ["Enable Mouseover Tooltip"] = "啟用滑鼠懸停工具提示",
   ["Enable Movable Bags"] = "啟用可移動包裹",
   ["Enable Offscreen Frame Positions"] = "啟用螢幕框架固定",
   ["Enable Overlap"] = "疊加顯示",