CAIRO (Reuters) - Qatar’s ruling Emir Sheikh Tamim bin Hamad al-Thani will attend a Gulf Arab summit in Saudi Arabia on Tuesday, the royal court said on Monday. The confirmation of his participation came after a Kuwaiti minister announced that Saudi Arabia would reopen its airspace and land and sea border to Qatar, citing a deal towards ending a dispute in which Riyadh and its allies imposed a boycott on Qatar since mid-2017.