test(csharp): add Statement.Cancel test

[birschick-bq]

What's Changed

• Added a test for Statement.Cancel
• Adds support for key-pair and Oauth authentication in the test configuration file.
• Updates Microsoft.NET.Test.Sdk reference to version 18.5.1
• Corrects indentation in the project file.
• Commit submodule reference to arrow-adbc has been updated to latest.

[Copilot]

Pull request overview

This PR extends the C# interop test suite by adding coverage for AdbcStatement.Cancel, and enhances the Snowflake test configuration helper to support additional authentication modes used by the interop tests.

Changes:

• Adds a new interop test validating AdbcStatement.Cancel behavior against a long-running Snowflake query.
• Extends SnowflakeTestingUtils.GetSnowflakeAdbcDriver to support JWT (key-pair) and OAuth authentication configuration.
• Updates the interop test project file formatting and bumps Microsoft.NET.Test.Sdk to 18.5.1.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
csharp/test/Interop/StatementTests.cs	New test coverage for statement cancellation using SYSTEM$WAIT queries.
csharp/test/Interop/SnowflakeTestingUtils.cs	Adds JWT and OAuth auth parameter population for Snowflake interop tests.
csharp/test/Interop/AdbcDrivers.Snowflake.Interop.Tests.csproj	Updates test SDK package version and normalizes indentation.

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[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

[CurtHagenlocher]

Can I assume that this test would have failed before recent driver changes?

[birschick-bq]

@CurtHagenlocher - You're correct. It would throw a NotSupported exception.