[SPARK-44904][PYTHON][DOCS] Correct the versionadded of `sql.functi…

…ons.approx_percentile` to 3.5.0

### What changes were proposed in this pull request?
`sql.functions.approx_percentile`  was introduced in SPARK-43941 (#41588). This is a pr for the Spark 3.5.0 and it does not belong to Spark 3.4.0. Therefore, this pr corrects the `versionadded` of `sql.functions.approx_percentile` to 3.5.0 and removed `versionchanged`.

### Why are the changes needed?
Correct the `versionadded` of `sql.functions.approx_percentile`.

### Does this PR introduce _any_ user-facing change?
No

### How was this patch tested?
Pass GitHub Actions

### Was this patch authored or co-authored using generative AI tooling?
No

Closes #42597 from LuciferYang/SPARK-44904.

Lead-authored-by: yangjie01 <yangjie01@baidu.com>
Co-authored-by: Hyukjin Kwon <gurwls223@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
(cherry picked from commit 534f9ea)
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>

python/pyspark/sql/functions.py

@@ -4523,10 +4523,11 @@ def approx_percentile(
     of `col` values is less than the value or equal to that value.
 
 
-    .. versionadded:: 3.1.0
+    .. versionadded:: 3.5.0
 
-    .. versionchanged:: 3.4.0
-        Supports Spark Connect.
+    Notes
+    -----
+    Supports Spark Connect.
 
     Parameters
     ----------