Bump OpenCover from 4.7.1204 to 4.7.1221 (#148)

Bumps [OpenCover](https://github.com/opencover/opencover) from 4.7.1204 to 4.7.1221.
- [Release notes](https://github.com/opencover/opencover/releases)
- [Changelog](https://github.com/OpenCover/opencover/blob/master/ReleaseNotes.tmp)
- [Commits](OpenCover/opencover@4.7.1204...4.7.1221)

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

Signed-off-by: dependabot[bot] <support@github.com>

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

src/Dhgms.Nucleotide.UnitTests/Dhgms.Nucleotide.UnitTests.csproj

@@ -18,7 +18,7 @@
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
     <PackageReference Include="Moq" Version="4.16.1" />
     <PackageReference Include="NetTestRegimentation" Version="1.5.3" />
-    <PackageReference Include="OpenCover" Version="4.7.1204" />
+    <PackageReference Include="OpenCover" Version="4.7.1221" />
     <PackageReference Include="ReportGenerator" Version="4.8.10" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.analyzers" Version="0.10.0" />