build(deps): bump Nethereum.Util from 4.21.0 to 4.21.2 (#62)

Bumps [Nethereum.Util](https://github.com/Nethereum/Nethereum) from 4.21.0 to 4.21.2.
- [Release notes](https://github.com/Nethereum/Nethereum/releases)
- [Commits](Nethereum/Nethereum@4.21.0...4.21.2)

---
updated-dependencies:
- dependency-name: Nethereum.Util
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

swappy-bot/swappy-bot.csproj

@@ -66,7 +66,7 @@
       <PackageReference Include="Microsoft.Extensions.Logging" Version="8.0.0" />
       <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="8.0.0" />
       <PackageReference Include="NBitcoin" Version="7.0.37" />
-      <PackageReference Include="Nethereum.Util" Version="4.21.0" />
+      <PackageReference Include="Nethereum.Util" Version="4.21.2" />
       <PackageReference Include="Polly" Version="8.4.0" />
       <PackageReference Include="Pomelo.EntityFrameworkCore.MySql" Version="8.0.2" />
       <PackageReference Include="Serilog" Version="4.0.0" />