bug: config file generated by --generate-default-config contains removed and deprecated flags

[DmitriyLewen]

Description

Trivy includes all flags into config file when using --generate-default-config command.
But Trivy returns error for this config file:

➜ trivy image   
2024-12-03T12:44:48-07:00       INFO    Loaded  file_path="trivy.yaml"
2024-12-03T12:44:48-07:00       ERROR   "--reset" was removed. Use "trivy clean --all" instead.
2024-12-03T12:44:48-07:00       FATAL   Fatal error     flag error: db flag error: unable to parse flag: removed flag ("--reset")

We need to exclude removed and obsolete flags from the generated configuration file.

Discussed in #8035

[dupuyarc]

Although this bug was closed, I am seeing these errors in v0.58.2, and there were other problems with the generation that the original bug reporter didn't encounter, please see my comment in discussion 8035 for details, summary quoted below:

The generated config file should work with the same version of trivy used to generate it.

Also, the configuration generator should at least

1. Issue a warning that the default ignore file doesn't exist, or
2. Create the file if it doesn't exist.
3. Alternately trivy could consider non-existence of a configured ignore file a non-fatal error.

My preference would be for (1) but any of these would be acceptable.

Finally, the generated config file sets the option to generate a config file, which fails (since it now exists).