Update Swashbuckle.AspNetCore and fix gRPC Swagger test compatibility

[Youssef1313]

Update Swashbuckle.AspNetCore and fix gRPC Swagger test compatibility

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Update Swashbuckle and align gRPC Swagger tests

Description

Updates Swashbuckle.AspNetCore to 10.2.1 while the work in #67134 is still pending.

Also includes the follow-up fixes needed in Microsoft.AspNetCore.Grpc.Swagger.Tests to match the newer OpenAPI surface used by the upgraded package, including the namespace change to Microsoft.OpenApi and tag assertions that no longer rely on indexed access.

[Youssef1313]

cc @martincostello

[Copilot]

Pull request overview

Updates the centrally-managed Swashbuckle.AspNetCore dependency version used across the repo, aligning the build’s external dependency set with a newer upstream release while the gRPC Swagger deprecation work (Issue #67134) is still pending.

Changes:

• Bump Swashbuckle.AspNetCore from 6.6.2 to 10.2.1 via eng/Versions.props.

[wtgodbe]

May need to kick off a run of https://dev.azure.com/dnceng/internal/_build?definitionId=931&_a=summary to get the package mirrored

[Youssef1313]

May need to kick off a run of https://dev.azure.com/dnceng/internal/_build?definitionId=931&_a=summary to get the package mirrored

Looks like it's already in dotnet-public since 2nd June.

[Youssef1313]

This is multiple major (breaking change) releases upgrade. If we are impacted by too much breaking changes, it might not be worth spending the time to fix those. Waiting for CI to tell.

[martincostello]

The breaking changes should all be related to the upgrade from Microsoft.OpenApi v1 ➡️ v2.

[Youssef1313]

@copilot Try to address the build errors in Microsoft.AspNetCore.Grpc.Swagger.Tests

[Copilot]

@copilot Try to address the build errors in Microsoft.AspNetCore.Grpc.Swagger.Tests

Addressed in 6e4680f. The Grpc Swagger test project now uses the newer Microsoft.OpenApi namespace and no longer assumes swagger.Tags is indexable under the updated OpenAPI surface.