[NWD] Update library versions in EPPlus/NetCoreTests

Fixes: b/228778281
Fixes: b/228778322
Fixes: b/228778323
Fixes: b/228778704
Fixes: b/228778767
Fixes: b/228778805
Release Note: No

Change-Id: I8e3188fbed531dada86447aa9a9d932ae5e79fdd

NetCoreTests/NetCoreTests.csproj

diff --git a/NetCoreTests/NetCoreTests.csproj b/NetCoreTests/NetCoreTests.csproj
index a8daf6d..4ae4dbc 100644
--- a/NetCoreTests/NetCoreTests.csproj
+++ b/NetCoreTests/NetCoreTests.csproj
@@ -9,7 +9,9 @@
     <PackageReference Include="MSTest.TestAdapter" Version="2.2.8"/>
     <PackageReference Include="MSTest.TestFramework" Version="2.2.8" />
     <PackageReference Include="Microsoft.NET.Test.SDK" Version="17.1.0"/>
+    <PackageReference Include="System.Net.Http" Version="4.3.4"/>
     <PackageReference Include="System.Text.Encoding.CodePages" Version="4.3.0" />
+    <PackageReference Include="System.Text.RegularExpressions" Version="4.3.1"/>
 
     <ProjectReference Include="..\EPPlus\EPPlusSDK.csproj" />