Bump xunit from 2.4.1 to 2.7.1

Bumps [xunit](https://github.com/xunit/xunit) from 2.4.1 to 2.7.1.
- [Commits](xunit/xunit@2.4.1...2.7.1)

---
updated-dependencies:
- dependency-name: xunit
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

tests/NRedisStack.Tests/NRedisStack.Tests.csproj

@@ -24,8 +24,8 @@
     <PackageReference Include="NetTopologySuite" Version="2.5.0" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />
     <PackageReference Include="StackExchange.Redis" Version="2.6.122" />
-    <PackageReference Include="xunit" Version="2.4.1" />
-    <PackageReference Include="xunit.assert" Version="2.4.1" />
+    <PackageReference Include="xunit" Version="2.7.1" />
+    <PackageReference Include="xunit.assert" Version="2.7.1" />
     <PackageReference Include="BouncyCastle.Cryptography" Version="2.2.0" />
   </ItemGroup>