fix: avoid usage of .unwrap in Rust solutions

challenges/sorting-algorithms/solutions/rust/function/src/main.rs

@@ -4,8 +4,11 @@ fn main() {
     let mut numbers: Vec<i64> = Vec::new();
     let stdin = io::stdin();
     for line in stdin.lock().lines().skip(1) {
-        let line = line.unwrap();
-        let number: i64 = line.trim().parse().unwrap();
+        let line = line.expect("Failed to read `stdin` line.");
+        let number: i64 = line
+            .trim()
+            .parse()
+            .expect("Failed to convert `number` as an `i64`.");
         numbers.push(number);
     }
     numbers.sort();