Merge #2046

2046: Fix a compilation error (maybe temporary) r=adrien-zinger a=adrien-zinger

It seems that we need to change something quick! The standard library will pass over

```bash
   Compiling massa_consensus v0.1.0 (/home/adrien/Documents/repos/massa/massa-consensus)
warning: an associated function with this name may be added to the standard library in the future
   --> massa-consensus/src/pos.rs:522:37
    |
522 |         let bits_u8_len = n_entries.div_ceil(&u8::BITS) as usize;
    |                                     ^^^^^^^^
    |
    = note: `#[warn(unstable_name_collisions)]` on by default
    = warning: once this associated item is added to the standard library, the ambiguity may cause an error or change in behavior!
    = note: for more information, see issue #48919 <rust-lang/rust#48919>
    = help: call with fully qualified syntax `num::Integer::div_ceil(...)` to keep using the current method
    = help: add `#![feature(int_roundings)]` to the crate attributes to enable `core::num::<impl u32>::div_ceil`
```

Opt for the fully qualified syntax

Co-authored-by: Adrien Zinger <zinger.ad@gmail.com>

massa-consensus/src/lib.rs

@@ -7,6 +7,7 @@
 #![feature(bool_to_option)]
 #![feature(hash_drain_filter)]
 #![feature(map_first_last)]
+#![feature(int_roundings)]
 
 #[macro_use]
 extern crate massa_logging;

massa-consensus/src/pos.rs

@@ -15,7 +15,6 @@ use massa_models::{
 };
 use massa_signature::derive_public_key;
 use num::rational::Ratio;
-use num::Integer;
 use rand::distributions::Uniform;
 use rand::Rng;
 use rand_xoshiro::rand_core::SeedableRng;
@@ -519,7 +518,7 @@ impl DeserializeCompact for ThreadCycleState {
                 "invalid number entries when deserializing ExportThreadCycleStat rng_seed".into(),
             ));
         }
-        let bits_u8_len = n_entries.div_ceil(&u8::BITS) as usize;
+        let bits_u8_len = n_entries.div_ceil(u8::BITS) as usize;
         if buffer[cursor..].len() < bits_u8_len {
             return Err(ModelsError::SerializeError(
                 "too few remaining bytes when deserializing ExportThreadCycleStat rng_seed".into(),