panic: send on closed channel

[knqyf263]

The DB build is failing now.
https://github.com/aquasecurity/trivy-java-db/actions/runs/11004543211

2024/09/21 00:22:35 Count: 252000
2024/09/21 00:22:37 Count: 253000
panic: send on closed channel

goroutine 8560966 [running]:
github.com/aquasecurity/trivy-java-db/pkg/crawler.(*Crawler).Crawl.func2.2({0xc004e56690?, 0x4e?})
	/home/runner/work/trivy-java-db/trivy-java-db/pkg/crawler/crawler.go:104 +0x108
created by github.com/aquasecurity/trivy-java-db/pkg/crawler.(*Crawler).Crawl.func2
	/home/runner/work/trivy-java-db/trivy-java-db/pkg/crawler/crawler.go:100 +0xa9
make: *** [Makefile:16: db-crawl] Error 2