Restore accidentally removed method Block::to_ne_bytes (#8211)

This method was removed in #7824, which introduced an optimized code
path for writing bloom filters on little-endian architectures. The
method was however still used in the big-endian code-path. Due to the
use of `#[cfg(target_endian)]` this went unnoticed in CI.

Fixes #8207

Author: jhorstmann

parquet/src/bloom_filter/mod.rs

@@ -119,6 +119,13 @@ impl Block {
         Self(result)
     }
 
+    #[inline]
+    #[cfg(not(target_endian = "little"))]
+    fn to_ne_bytes(self) -> [u8; 32] {
+        // SAFETY: [u32; 8] and [u8; 32] have the same size and neither has invalid bit patterns.
+        unsafe { std::mem::transmute(self.0) }
+    }
+
     #[inline]
     #[cfg(not(target_endian = "little"))]
     fn to_le_bytes(self) -> [u8; 32] {