Bump xunit.extensibility.execution and xunit.extensibility.core (#337)

Bumps [xunit.extensibility.execution](https://github.com/xunit/xunit) and [xunit.extensibility.core](https://github.com/xunit/xunit). These dependencies needed to be updated together.

Updates `xunit.extensibility.execution` from 2.6.6 to 2.7.0
- [Commits](xunit/xunit@2.6.6...2.7.0)

Updates `xunit.extensibility.core` from 2.6.6 to 2.7.0
- [Commits](xunit/xunit@2.6.6...2.7.0)

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

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

Directory.Packages.props

@@ -32,8 +32,8 @@
     <PackageVersion Include="xunit" Version="2.6.6" />
     <PackageVersion Include="xunit.runner.console" Version="2.7.0" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.5.6" />
-    <PackageVersion Include="xunit.extensibility.core" Version="2.6.6" />
-    <PackageVersion Include="xunit.extensibility.execution" Version="2.6.6" />
+    <PackageVersion Include="xunit.extensibility.core" Version="2.7.0" />
+    <PackageVersion Include="xunit.extensibility.execution" Version="2.7.0" />
     <!-- https://dev.azure.com/tonerdo/coverlet/_artifacts/feed/coverlet-nightly/NuGet/coverlet.collector -->
     <PackageVersion Include="coverlet.collector" Version="6.0.1-preview.43.g52ddde6e8d" />
     <PackageVersion Include="MSTest" Version="2.2.10" />