[Smoke Tests] Update target frameworks (Azure#36050)

The focus of these changes is to update the target frameworks to replace `net461` with `net462` now that the former has gone out of support.

Author: jsquire

common/SmokeTests/SmokeTest/SmokeTest.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFrameworks>net7.0;net6.0;net461</TargetFrameworks>
+    <TargetFrameworks>net7.0;net6.0;net462</TargetFrameworks>
     <LangVersion>11.0</LangVersion>
     <NoWarn>$(NoWarn);NU1605</NoWarn>
   </PropertyGroup>