fix: remove unused lines of no.354 (#3864)

Author: Ashioto

solution/0300-0399/0354.Russian Doll Envelopes/README.md

@@ -76,8 +76,6 @@ class Solution:
                 d.append(h)
             else:
                 idx = bisect_left(d, h)
-                if idx == len(d):
-                    idx = 0
                 d[idx] = h
         return len(d)
 ```

solution/0300-0399/0354.Russian Doll Envelopes/README_EN.md

@@ -74,8 +74,6 @@ class Solution:
                 d.append(h)
             else:
                 idx = bisect_left(d, h)
-                if idx == len(d):
-                    idx = 0
                 d[idx] = h
         return len(d)
 ```

solution/0300-0399/0354.Russian Doll Envelopes/Solution.py

@@ -7,7 +7,5 @@ def maxEnvelopes(self, envelopes: List[List[int]]) -> int:
                 d.append(h)
             else:
                 idx = bisect_left(d, h)
-                if idx == len(d):
-                    idx = 0
                 d[idx] = h
         return len(d)