Update Bicep CLI version from 0.41.2 to 0.42.1.

Release: https://github.com/Azure/bicep/releases/tag/v0.42.1

Files to update

• cli/azd/pkg/tools/bicep/bicep.go — update Version variable to 0.42.1
• .github/workflows/lint-bicep.yml — update download URL to v0.42.1