By Ted Hesson WASHINGTON (Reuters) – U.S. Homeland Security Secretary Alejandro Mayorkas will come under scrutiny on Wednesday as a Republican-led House of Representatives committee moves to impeach him over allegations he has encouraged illegal immigration with overly lax policies. Republican attorneys general from Missouri, Montana and Oklahoma will testify at a hearing focused on the Republican claim that Mayorkas – Democratic President Joe Biden’s top border official – has refused to enforce immigration laws passed by Congress. It is extremely rare for a U.S. Cabinet secretary to be subjec…