Use the newly stabilized div_ceil

Sets a msrv of 1.73.0.

crypto/transcript/src/lib.rs

@@ -149,7 +149,7 @@ where
 
     // block_size returns the block_size in bytes
     // Use a ceil div in case the block size isn't evenly divisible by our word size
-    let words = (D::block_size() + (WORD_SIZE - 1)) / WORD_SIZE;
+    let words = D::block_size().div_ceil(WORD_SIZE);
     for _ in 0 .. (2 * words) {
       self.0.update([255; WORD_SIZE]);
     }