update assembly version

Author: smdn

src/Smdn.Fundamental.UInt24n/Smdn.Fundamental.UInt24n.csproj

@@ -5,7 +5,7 @@ SPDX-License-Identifier: MIT
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <TargetFrameworks>net8.0;net6.0;net45;netstandard2.1;netstandard2.0;netstandard1.6</TargetFrameworks>
-    <VersionPrefix>3.1.0</VersionPrefix>
+    <VersionPrefix>4.0.0</VersionPrefix>
     <VersionSuffix></VersionSuffix>
     <PackageValidationBaselineVersion>3.1.0</PackageValidationBaselineVersion>
     <RootNamespace/> <!-- empty the root namespace so that the namespace is determined only by the directory name, for code style rule IDE0030 -->