Minor: Delete old cume_dist and percent_rank docs (#13137)

* Delete cume_dist and percent_rank docs

* fix docs

Author: jonathanc-n

docs/source/user-guide/sql/window_functions.md

@@ -148,28 +148,10 @@ All [aggregate functions](aggregate_functions.md) can be used as window function
 
 ## Analytical functions
 
-- [cume_dist](#cume_dist)
-- [percent_rank](#percent_rank)
 - [first_value](#first_value)
 - [last_value](#last_value)
 - [nth_value](#nth_value)
 
-### `cume_dist`
-
-Relative rank of the current row: (number of rows preceding or peer with current row) / (total rows).
-
-```sql
-cume_dist()
-```
-
-### `percent_rank`
-
-Relative rank of the current row: (rank - 1) / (total rows - 1).
-
-```sql
-percent_rank()
-```
-
 ### `first_value`
 
 Returns value evaluated at the row that is the first row of the window frame.