make config file not required

[joao-zanutto]

No description provided.

[wwoytenko]

I checked that when you try to set the env vars with AutomaticEnv if they are not presented in the config then the config attribute value won't be gathered from the env vars.

For example:

$ COMMON_PG_BIN_PATH='/opt/homebrew/Cellar/postgresql@16/16.1_3/bin' ./greenmask dump                 
2024-04-02T12:14:22+02:00 INF stderr forwarding Executable=pg_dump Stderr="pg_dump: error: server version: 16.1 (Debian 16.1-1.pgdg120+1); pg_dump version: 14.9 (Homebrew)"
2024-04-02T12:14:22+02:00 INF stderr forwarding Executable=pg_dump Stderr="pg_dump: error: aborting because of server version mismatch"
2024-04-02T12:14:22+02:00 FTL cannot make a backup error="schema only stage dumping error: cannot execute command: exit status 1"

Consider adding the possibility to set the config attributes (at least temp dir and pg_bin_path) via env vars.

[wwoytenko]

LGTM