President Biden on Sunday used what is normally a festive St. Patrick’s Day celebration at the White House to acknowledge the growing international concern, including among the Irish, over the humanitarian situation of Palestinians amid Israel’s military action in Gaza.“The taoiseach and I agree about the urgent need to increase humanitarian aid in Gaza and get the cease-fire deal,” Mr. Biden said alongside Leo Varadkar, Ireland’s prime minister, or taoiseach, an outspoken critic of Israel’s war against Hamas in response to the Oct. 7 terrorist attack. As hundreds of Irish…