Fix IDE0360 example: only simplify get accessor, preserve set with validation (#50364)

* Initial plan

* Fix IDE0360 documentation example - only simplify get accessor

Co-authored-by: gewarren <[email protected]>

* Update docs/fundamentals/code-analysis/style-rules/ide0360.md

Co-authored-by: Copilot <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: gewarren <[email protected]>
Co-authored-by: Copilot <[email protected]>

Author: 3 people

docs/fundamentals/code-analysis/style-rules/ide0360.md

@@ -49,7 +49,11 @@ public int Prop
 }
 
 // Fixed code.
-public int Prop { get; set; }
+public int Prop
+{
+    get;
+    set { field = (value > 0) ? value : throw new ArgumentException(); }
+}
 ```
 
 ## Suppress a warning