Re-translate the Japanese version (#1871)

* Retranslate Japanese docs with GPT-5.4

* Retranslate Japanese code with GPT-5.4

ja/codes/rust/chapter_dynamic_programming/climbing_stairs_dfs.rs

@@ -0,0 +1,29 @@
+/*
+ * File: climbing_stairs_dfs.rs
+ * Created Time: 2023-07-09
+ * Author: codingonion (coderonion@gmail.com)
+ */
+
+/* 検索 */
+fn dfs(i: usize) -> i32 {
+    // dp[1] と dp[2] は既知なので返す
+    if i == 1 || i == 2 {
+        return i as i32;
+    }
+    // dp[i] = dp[i-1] + dp[i-2]
+    let count = dfs(i - 1) + dfs(i - 2);
+    count
+}
+
+/* 階段登り：探索 */
+fn climbing_stairs_dfs(n: usize) -> i32 {
+    dfs(n)
+}
+
+/* Driver Code */
+pub fn main() {
+    let n: usize = 9;
+
+    let res = climbing_stairs_dfs(n);
+    println!("{n} 段の階段を上る方法は全部で {res} 通り");
+}