New apk registry

[sobolevn]

Here are some other projects that offer apk package registries. Required features:

• It must be free (because I cannot pay for any western services, because of the unlawful sanctions). Or it can be hosted in Russia or in any other friendly country, in this case I will be able to pay for them some reasonable price
• API access
• Public download link, something similar to what we have right now
• Security: code signing and stuff

Candidates (not full list):

• https://help.cloudsmith.io/docs/alpine-repository
• https://blog.packagecloud.io/packagecloud-a-well-suited-package-manager-for-alpine-linux

Refs:

• #895
• https://github.com/sobolevn/git-secret/issues/881
• https://github.com/sobolevn/git-secret/issues/878