feat: clean up the `last-error/data` folder

[jizusun]

After running for several days, I found the last-error folder become larger.
Looking into it, I found the last-error/data is not cleaned up.

relates to #6

root@237a1a19c734:/work# du -sh last-error
659M    last-error

root@237a1a19c734:/work# du -a last-error | sort -nr | head
675856  last-error
674388  last-error/data
4736    last-error/data/2843116c62115eaf84f0224be51d0f124e577561.zip
3116    last-error/data/51105568cfddac5f3f901bd84f6368abddb7d1af.zip
2972    last-error/data/6b775eb3f4a7a6de4381587af6cfcd2fed788b49.zip
2876    last-error/data/c78951daf4558c33d4ce2fbfec2011403747d419.zip
2844    last-error/data/a6c8e2a19c0c2da950ed67625a435a57d8b25be7.zip
2552    last-error/data/8f3d20a0a55affcd66e5c23f98b66e88bb057157.zip
2544    last-error/data/d056f920b8a2a2c137aed466b4b71ceb78836e63.zip
2344    last-error/data/3c66fd46f1722f9f8fe57cf3d8952c4966191905.zip