v13.0.0

• Added quill::log() to macro-free mode for logging with a runtime-selected log level.
• Added backend tag processing through PatternFormatterOptions::process_tags and support for constructing macro-free quill::Tags from std::string and std::string_view. (#970)
• Added opt-in thread migration to ManualBackendWorker for externally serialized executor and task-pool integrations. (#972)
• Avoided allocating physical pages for unused bounded queue scratch space until it is needed. (#979)
• Precompiled PatternFormatter fields when the formatter is created instead of parsing the pattern for every log record.
• Added a backend fast path for applications with a single active frontend thread context.
• Added Android NDK compile coverage for API 24 on arm64-v8a and x86_64.
• Improvements to frontend throughput for macro-free logging and backend throughput for filtering, structured logging, and reusable transit-event data.