chore(deps): bump Newtonsoft.Json in /src/IBM.Watson.Assistant.v1

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 12.0.3 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@12.0.3...13.0.1)

---
updated-dependencies:
- dependency-name: Newtonsoft.Json
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Diff for: src/IBM.Watson.Assistant.v1/IBM.Watson.Assistant.v1.csproj

@@ -36,7 +36,7 @@
     <ItemGroup>
         <PackageReference Include="IBM.Watson.Common" Version="6.0.0" />
         <PackageReference Include="IBM.Cloud.SDK.Core" Version="1.3.1" />
-        <PackageReference Include="Newtonsoft.Json" Version="12.0.3" />
+        <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
         <PackageReference Include="JsonSubTypes" Version="1.6.0" />
     </ItemGroup>