Deadcode linter

[arbulu89]

Description

Run golang deadcode process to find dead code paths and remove them.
https://pkg.go.dev/golang.org/x/tools/internal/cmd/deadcode

Here the fixed errors:
https://github.com/trento-project/agent/actions/runs/22100883779/job/63869965678?pr=552

3 things:

• Unfortunately there is no asdf plugin for golang deadcode, so we need to install and reshim manually
• deadcode always returns 0 return code (unless compliation errors), so we need to look for stdout to see if there are errors. That's why we have that comparison in the makefile file
• A lot of our functions are created to make the code testable, that's why we need to add the test flag. Otherwise we would have a lot of dead code

EDIT:
When @antgamdia suggested to add deadcode to the tools.go file to track the version, I have read that golang tooling usage has envolved quite a bit since 1.24.
Now, tools can be declared and tracked without any dummy file to import them, and use them as go tool {toolname}. This gives as the chance to remove some dependencies from asdf as well, and have all golang tooling in the same place.
If you want to read a bit more: https://blog.howardjohn.info/posts/go-tools-command/

[antgamdia]

comment : this way, we don't know which version of the linter we are using. While we might want to stick to the latest, it can often make our CI fail. Instead, we can define the deps in a non-compiled file, track them in our deps and install them via go install, something like:

//go:build tools

package tools

import (
	_ "golang.org/x/tools/cmd/deadcode"
)

dev-deps:
	go install \
		golang.org/x/tools/cmd/deadcode

[arbulu89]

this package was downversioned by the author:

go: warning: github.com/chigopher/pathlib@v1.0.0: retracted by module author: Published accidentally
go: to switch to the latest unretracted version, run:
	go get github.com/chigopher/pathlib@latest

[gagandeepb]

Thanks for this.This could be evolved to have a deadcode_ignore file containing either files or file-path-patterns to ignore for the purposes of deadcode analysis.

[antgamdia]

Thanks for adding the suggestions and for looking into the go tool thing!