Update AV1520 guideline (#360)

Split from #298.

Co-authored-by: Dennis Doomen <dennis.doomen@greenchoice.nl>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: 3 people

_rules/1520.md

@@ -4,8 +4,8 @@ rule_category: maintainability
 title: Only use `var` when the type is evident
 severity: 1
 ---
-Use `var` for anonymous types (typically resulting from a LINQ query), or if the type is [evident](https://www.jetbrains.com/help/resharper/2021.3/Using_var_Keyword_in_Declarations.html#use-var-when-evident-details).
-Never use `var` for [built-in types](https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/built-in-types).
+Use `var` for anonymous types (typically resulting from a LINQ query), or if the type is [evident](https://www.jetbrains.com/help/resharper/Using_var_Keyword_in_Declarations.html#use-var-when-evident-details).
+Never use `var` for [built-in types](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/builtin-types/built-in-types).
 
 	// Projection into anonymous type.
 	var largeOrders =