Backups need more secure encryption

[Lexy2]

Currently the database backups are password-protected zips.
Zip format is known to use weak encryption and susceptible to brute-force attacks.

Let's compress our backups with something else, like p7zip with AES-256 and header encryption.

[Lexy2]

In addition, 7z offers x2 better compression ratio: for 110 Mb dump, zip is 22 Mb, 7z & xz are 10 Mb.
Also tried Brotli - 15 Mb and long compression time.