Remove variables used once.

js/src/dropdown.js

@@ -468,8 +468,7 @@ class Dropdown {
 
     if (!isActive || isActive && (event.which === ESCAPE_KEYCODE || event.which === SPACE_KEYCODE)) {
       if (event.which === ESCAPE_KEYCODE) {
-        const toggle = parent.querySelector(SELECTOR_DATA_TOGGLE)
-        $(toggle).trigger('focus')
+        $(parent.querySelector(SELECTOR_DATA_TOGGLE)).trigger('focus')
       }
 
       $(this).trigger('click')

js/src/tooltip.js

@@ -710,8 +710,7 @@ class Tooltip {
   }
 
   _handlePopperPlacementChange(popperData) {
-    const popperInstance = popperData.instance
-    this.tip = popperInstance.popper
+    this.tip = popperData.instance.popper
     this._cleanTipClass()
     this.addAttachmentClass(this._getAttachment(popperData.placement))
   }