fix: Fix typo on EuiComboBox is invalid class

Author: grodriguez85

packages/core/addon/components/eui-combo-box/index.hbs

@@ -71,7 +71,7 @@
     (if @compressed "euiComboBox--compressed")
     (if @fullWidth "euiComboBox--fullWidth")
     (if @isDisabled "euiComboBox-isDisabled")
-    (if @isInvalid "euiComboBox--isInvalid")
+    (if @isInvalid "euiComboBox-isInvalid")
     (if this.select.isOpen "euiComboBox-isOpen")
   }}
   @noMatchesMessageComponent={{if