Add TSA options file and fix release pipeline TSA onboarding failure

[Copilot]

The release pipeline was failing because the auto-generated TSA codebase name (microsoft_Apps_microsoft/winget-create) contains /, which TSA rejects. Fix is to supply an explicit TSA config file so the codebase name is controlled.

Changes

• .config/tsaoptions.json — new checked-in TSA config specifying the correct repositoryName, ADO project/area/iteration paths, and notification alias; ignoreBranchName: true prevents branch-specific codebase variants
• pipelines/azure-pipelines.release.yml — adds globalSdl.tsa block under extends.parameters pointing at the config file:

  globalSdl:
    tsa:
      enabled: true
      configFile: $(Build.SourcesDirectory)\.config\tsaoptions.json
      onboard: false

• .github/actions/spelling/allow.txt — adds tsa and tsaoptions to unblock the check-spelling CI check