Fix clippy (#15489)

# Description
There are some clippy(version 0.1.86) errors on nushell repo. This pr is
trying to fix it.

# User-Facing Changes
Hopefully none.

# Tests + Formatting
NaN

# After Submitting
NaN

crates/nu-cmd-extra/src/extra/bits/mod.rs

@@ -135,7 +135,7 @@ where
                 (min, max) => (rhs, lhs, max, min),
             };
 
-            let pad = iter::repeat(0).take(max_len - min_len);
+            let pad = iter::repeat_n(0, max_len - min_len);
 
             let mut a;
             let mut b;

crates/nu-cmd-extra/src/extra/bits/shift_left.rs

@@ -249,7 +249,7 @@ fn shift_bytes_and_bits_left(data: &[u8], byte_shift: usize, bit_shift: usize) -
             Last | Only => lhs << bit_shift,
             _ => (lhs << bit_shift) | (rhs >> (8 - bit_shift)),
         })
-        .chain(iter::repeat(0).take(byte_shift))
+        .chain(iter::repeat_n(0, byte_shift))
         .collect::<Vec<u8>>()
 }