fix: zeronet/Dockerfile to reduce vulnerabilities
The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE314-BUSYBOX-1920734
- https://snyk.io/vuln/SNYK-ALPINE314-BUSYBOX-1920744
- https://snyk.io/vuln/SNYK-ALPINE314-BUSYBOX-1920745
- https://snyk.io/vuln/SNYK-ALPINE314-BUSYBOX-1920755
- https://snyk.io/vuln/SNYK-ALPINE314-UTILLINUX-1912784