Prefer `TestCleanup` over `Dispose`/`DisposeAsync` method

[Evangelink]

Enabled by default: false
Default severity: Info
Title: Prefer TestCleanup methods over Dispose/DisposeAsync

Flags any usage of Dispose or DisposeAsync on classes marked with [TestClass].

AB#1994935

[testplatform-bot]

✅ Successfully linked to Azure Boards work item(s):

• User Story 1994935