lower the baseline version for system.text.encodings.web (#49671)

* lower the baseline version

* pin ref assembly version to 5.0.0.0

* adding condition for netfx

* Update src/libraries/pkg/baseline/packageIndex.json

Co-authored-by: Eric StJohn <[email protected]>

* correct the condition

Co-authored-by: Eric StJohn <[email protected]>

Author: Anipik

Diff for: src/libraries/System.Text.Encodings.Web/ref/System.Text.Encodings.Web.csproj

@@ -3,6 +3,7 @@
     <TargetFrameworks>$(NetCoreAppCurrent);netstandard2.0;net461</TargetFrameworks>
     <ExcludeCurrentNetCoreAppFromPackage>true</ExcludeCurrentNetCoreAppFromPackage>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <AssemblyVersion Condition="!$(TargetFramework.StartsWith('net4'))">5.0.0.0</AssemblyVersion>
     <!-- Only CLS-compliant members can be abstract -->
     <NoWarn>$(NoWarn);CS3011</NoWarn>
     <Nullable>enable</Nullable>
@@ -20,4 +21,4 @@
     <PackageReference Include="System.Buffers" Version="$(SystemBuffersVersion)" />
     <PackageReference Include="System.Memory" Version="$(SystemMemoryVersion)" />
   </ItemGroup>
-</Project>
+</Project>