Alpine installed is too generic and might be conflict with other files with the same name

[another-rex]

See #107 (comment)

A potential solution suggested there is:

G-Rath:
I wonder if this should be handled similar to git, sboms and csvs in osv-detector (which are a parser located in lockfile, but are never assumed when scanning directories - you have to explicitly say "this is a CSV I want you to check") - because /lib/apk/db/installed is very specific, so you're only ever going to get it checked if you run the scanner from anywhere along that path with -r anyway

So what if instead it had a dedicated flag, like --check-apk-installed?

#94 could then be used as a way of telling the scanner to treat arbitrary files as installed, but the scanner would never automatically assume a file called installed should be parsed as-such