branch out RNG when measuring (dragoon/komodo!130)

- addresses #9 
- needed !133 to work

this MR simply adds `+ Clone` to `rng` and removes the `mut` from the `rng` of the `measure_inbreeding` function.

running the same snippet of code from #9 yields the following two images with a schedule of $1$ and $5$ respectively

![000_1.1](/uploads/ace74e299c6d4374df713ab5004f3c1d/000_1.1.png)
![000_1.2](/uploads/c784f5b62c41004971fd3048f7b5babc/000_1.2.png)

we see that all measurements on $t$ where $t = 0 \mod 5$ are the same in both images 

bins/inbreeding/src/main.rs

@@ -38,15 +38,17 @@ fn measure_inbreeding<F: PrimeField>(
     nb_measurements: usize,
     mp: &MultiProgress,
     sty: &ProgressStyle,
-    rng: &mut impl RngCore,
+    rng: &(impl RngCore + Clone),
 ) -> f64 {
+    let mut rng = rng.clone();
+
     let mut count = 0;
 
     let pb = mp.add(ProgressBar::new(nb_measurements as u64));
     pb.set_style(sty.clone());
     pb.set_message("measure");
     for _ in 0..nb_measurements {
-        if fec::decode(draw_unique_elements(shards, k, rng)).is_ok() {
+        if fec::decode(draw_unique_elements(shards, k, &mut rng)).is_ok() {
             count += 1;
         }
         pb.inc(1);
@@ -62,7 +64,7 @@ fn end_to_end<F, Fun>(
     max_t: usize,
     nb_measurements: usize,
     measurement_schedule: Fun,
-    rng: &mut impl RngCore,
+    rng: &mut (impl RngCore + Clone),
 ) -> Result<(), KomodoError>
 where
     F: PrimeField,
@@ -109,7 +111,7 @@ fn recoding<F, Fun>(
     env: Environment,
     nb_measurements: usize,
     measurement_schedule: Fun,
-    rng: &mut impl RngCore,
+    rng: &mut (impl RngCore + Clone),
 ) -> Result<(), KomodoError>
 where
     F: PrimeField,