Merge pull request #15752 from michaelnebel/csharp/updatesupportedlanguages

C#: Claim suppport for C# 12 / .NET 8.

docs/codeql/reusables/supported-versions-compilers.rst

@@ -11,11 +11,11 @@
    Microsoft extensions (up to VS 2019),
 
    Arm Compiler 5 [4]_","``.cpp``, ``.c++``, ``.cxx``, ``.hpp``, ``.hh``, ``.h++``, ``.hxx``, ``.c``, ``.cc``, ``.h``"
-   C#,C# up to 11,"Microsoft Visual Studio up to 2019 with .NET up to 4.8,
+   C#,C# up to 12,"Microsoft Visual Studio up to 2019 with .NET up to 4.8,
 
    .NET Core up to 3.1
 
-   .NET 5, .NET 6, .NET 7","``.sln``, ``.csproj``, ``.cs``, ``.cshtml``, ``.xaml``"
+   .NET 5, .NET 6, .NET 7, .NET 8","``.sln``, ``.csproj``, ``.cs``, ``.cshtml``, ``.xaml``"
    Go (aka Golang), "Go up to 1.21", "Go 1.11 or more recent", ``.go``
    Java,"Java 7 to 21 [5]_","javac (OpenJDK and Oracle JDK),