add net462 target framework

Author: phnx47

src/Prometheus.Client.DependencyInjection.csproj

@@ -1,14 +1,17 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard2.0;net6.0;net8.0</TargetFrameworks>
+    <TargetFrameworks>net462;netstandard2.0;net6.0;net8.0</TargetFrameworks>
     <Description>Dependency Injection extensions for Prometheus.Client</Description>
     <RepositoryUrl>https://github.com/prom-client-net/prom-client-dependencyinjection</RepositoryUrl>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
   <ItemGroup>
     <PackageReference Include="Prometheus.Client" Version="5.2.0" />
-    <PackageReference Condition="'$(TargetFramework)' == 'netstandard2.0'" Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="3.1.32" />
-    <PackageReference Condition="'$(TargetFramework)' == 'net6.0'" Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="6.0.0" />
-    <PackageReference Condition="'$(TargetFramework)' == 'net8.0'" Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="8.0.2" />
+    <PackageReference Condition="'$(TargetFramework)' == 'net462' OR '$(TargetFramework)' == 'netstandard2.0'"
+                      Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="3.1.32" />
+    <PackageReference Condition="'$(TargetFramework)' == 'net6.0'"
+                      Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="6.0.0" />
+    <PackageReference Condition="'$(TargetFramework)' == 'net8.0'"
+                      Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="8.0.2" />
   </ItemGroup>
 </Project>