chore: suppress MSB3277 warnings (dotnet#2926)

Author: filzrev

tests/BenchmarkDotNet.IntegrationTests.ManualRunning.MultipleFrameworks/BenchmarkDotNet.IntegrationTests.ManualRunning.MultipleFrameworks.csproj

@@ -6,6 +6,8 @@
     <TargetFrameworks>net461;net48;netcoreapp2.0;net8.0</TargetFrameworks>
     <!-- Deprecated runtime and vulnerabilities from old runtime, just in case any are found in the future. -->
     <NoWarn>$(NoWarn);NETSDK1138;NU1903</NoWarn>
+    <!-- Suppress warning MSB3277: Found conflicts between different versions of "System.Buffers" that could not be resolved. -->
+    <MSBuildWarningsAsMessages>$(MSBuildWarningsAsMessages);MSB3277</MSBuildWarningsAsMessages>
     <TreatWarningsAsErrors>false</TreatWarningsAsErrors>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <AssemblyName>BenchmarkDotNet.IntegrationTests.ManualRunning.MultipleFrameworks</AssemblyName>