WASHINGTON, May 17 (Reuters) - Florida Republican Governor Ron DeSantis will officially enter the 2024 U.S. presidential race next week, according to two sources familiar with the decision, immediately becoming Donald Trump's biggest rival for the Republican nomination and shaking up a contest that largely has been one-sided. DeSantis will likely file paperwork declaring his candidacy on May 25 to coincide with a donor meeting in Miami, with a more formal launch the week of May 29, according to a source. The invitation for the May 25 event stated that donors would be put to “work,” an apparent allusion to...