Bump Argon and Verify.XunitV3 in /src (#826)

Bumps [Argon](https://github.com/SimonCropp/Argon) and [Verify.XunitV3](https://github.com/VerifyTests/Verify). These dependencies needed to be updated together.

Updates `Argon` from 0.26.0 to 0.26.0
- [Release notes](https://github.com/SimonCropp/Argon/releases)
- [Commits](SimonCropp/Argon@0.26.0...0.26.0)

Updates `Verify.XunitV3` from 28.6.1 to 28.7.0
- [Release notes](https://github.com/VerifyTests/Verify/releases)
- [Commits](VerifyTests/Verify@28.6.1...28.7.0)

---
updated-dependencies:
- dependency-name: Argon
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: Verify.XunitV3
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

src/Directory.Packages.props

@@ -21,7 +21,7 @@
     <PackageVersion Include="Polyfill" Version="7.8.0" />
     <PackageVersion Include="ProjectDefaults" Version="1.0.147" />
     <PackageVersion Include="Verify.SqlServer" Version="10.1.0" />
-    <PackageVersion Include="Verify.XunitV3" Version="28.6.1" />
+    <PackageVersion Include="Verify.XunitV3" Version="28.7.0" />
     <PackageVersion Include="xunit.v3" Version="1.0.0" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.0.0" />
   </ItemGroup>