Update Go solution for 0011, 0104

[hamorrar]

• File(s) Modified: 0011-container-with-the-most-water.go, 0104-maximum-depth-of-binary-tree.go
• Language(s) Used: go
• Submission URL: https://leetcode.com/problems/container-with-most-water/submissions/1686430793/
• Submission URL: https://leetcode.com/problems/maximum-depth-of-binary-tree/submissions/1688779077/

Note: the code is pretty much the same. Just updating to simplify with newer Go versions.