Drop emit of last semicolon in single-line object literal types

Tracking follow-up to #33402

When synthetic object literal type nodes are printed on a single line, they come out like

type X = { a: string; b: string; };

While working on semicolon formatting features, I briefly had the formatter remove the semicolon after b: string;. The result was well-received but I ultimately decided the logic didn’t belong in the formatter; if this was going to be the canonical formatting of single-line object type literals, they should simply come out of the emitter that way.