Upgrade NEST version to support elastic 7

fix startup exception "ArgumentException: Requested value 'data_cold' was not found" which the NEST V7.5.1 library doesn't have all new elastic roles enum mappings

Author: EngRslan

src/providers/WorkflowCore.Providers.Elasticsearch/WorkflowCore.Providers.Elasticsearch.csproj

@@ -13,7 +13,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="2.2.0" />
-    <PackageReference Include="NEST" Version="7.5.1" />
+    <PackageReference Include="NEST" Version="7.14.1" />
   </ItemGroup>
 
   <ItemGroup>