Remove duplicate non-default scaffold assertions

[cdcavell]

Summary

Removes the duplicated none + sqlserver scaffold validation path from the template-smoke-test job.

The template-option-matrix job already provides authoritative coverage for template option combinations through eng/Assert-TemplateOptionScaffold.ps1, including authentication settings, database provider selection, connection-string selection, SQL Server migration omission, migration-test absence, and migration-namespace-reference checks.

Changes

• Removed the Linux-only ContosoNoAuthSqlServer scaffold step from template-smoke-test.
• Removed the duplicated inline PowerShell assertions for the non-default scaffold.
• Removed the redundant non-default restore, build, and test steps from the smoke-test job.
• Preserved the existing cross-platform default scaffold/build/test coverage.
• Preserved Linux Docker build, Compose validation, application startup, and health-check coverage.
• Left template-option-matrix as the single source of truth for template option semantics.

Rationale

Maintaining two separate implementations of the same option-specific assertions creates unnecessary CI duplication and increases the risk that the inline smoke-test checks drift from the shared assertion script.

This change clarifies CI responsibilities:

• template-smoke-test validates package installation, default scaffold behavior, cross-platform build/test behavior, and Linux Docker/Compose execution.
• template-option-matrix validates authentication and database option combinations and their generated scaffold semantics.

Validation

• Confirmed Assert-TemplateOptionScaffold.ps1 retains SQL Server migration omission, migration-test absence, and migration-namespace-reference validation.
• Confirmed the none + sqlserver combination remains covered by template-option-matrix.
• Verified the generated patch with git apply --check.

Closes #531.