Fix Blazor build by bumping AngleSharp dependency

[jattasNI]

Pull Request

🤨 Rationale

PR builds (example) and local builds of main are failing with these errors:

@ni-private/blazor-workspace:build: /home/runner/work/nimble/nimble/packages/blazor-workspace/Tests/OkBlazor.Tests/OkBlazor.Tests.csproj : error NU1902: Warning As Error: Package 'AngleSharp' 1.4.0 has a known moderate severity vulnerability, https://github.com/advisories/GHSA-pgww-w46g-26qg [/home/runner/work/nimble/nimble/packages/blazor-workspace/BlazorWorkspace.slnx]
@ni-private/blazor-workspace:build: /home/runner/work/nimble/nimble/packages/blazor-workspace/Tests/SprightBlazor.Tests/SprightBlazor.Tests.csproj : error NU1902: Warning As Error: Package 'AngleSharp' 1.4.0 has a known moderate severity vulnerability, https://github.com/advisories/GHSA-pgww-w46g-26qg [/home/runner/work/nimble/nimble/packages/blazor-workspace/BlazorWorkspace.slnx]
@ni-private/blazor-workspace:build: /home/runner/work/nimble/nimble/packages/blazor-workspace/Tests/NimbleBlazor.Tests/NimbleBlazor.Tests.csproj : error NU1902: Warning As Error: Package 'AngleSharp' 1.4.0 has a known moderate severity vulnerability, https://github.com/advisories/GHSA-pgww-w46g-26qg [/home/runner/work/nimble/nimble/packages/blazor-workspace/BlazorWorkspace.slnx]

The cause is this vulnerability in AngleSharp, which is pulled in by our dependency on bunit. This seems correct anyway since some test code uses it but relies on the transitive dependency to cause it to be present.

👩‍💻 Implementation

We are on the latest bunit so the only way I'm aware to fix this is to explicitly depend on AngleSharp in order to request the latest version.

🧪 Testing

Local and PR builds pass.

✅ Checklist

• I have updated the project documentation to reflect my changes or determined no changes are needed.