Release v1.8.4

What's Changed

• Fix CI for pip install by @csukuangfj in #371
• Fix CI test for Go. by @csukuangfj in #372
• Add C API for offline TTS. by @csukuangfj in #373
• Test go inside sherpa-onnx by @csukuangfj in #374
• Add ccache to CI by @csukuangfj in #375
• Support printing input text and words after splitting by @csukuangfj in #376
• Add Go API for TTS by @csukuangfj in #377

Full Changelog: v1.8.3...v1.8.4