refactor(kernel): ignore the clippy::unusual_byte_groupings lint in ctz3_lut_nonzero

Author: yvt

src/r3_kernel/src/utils/ctz.rs

@@ -172,6 +172,7 @@ fn ctz3_lut(x: usize) -> u32 {
 /// `x` must be in range `1..8`.
 #[inline]
 // This code groups digits irregularly to express a specific meaning
+#[expect(clippy::unusual_byte_groupings)]
 #[allow(clippy::inconsistent_digit_grouping)]
 fn ctz3_lut_nonzero(x: usize) -> u32 {
     debug_assert!(x < 8);