refactor: remove c4autoconf

[ee7]

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• [x] Updated CHANGELOG.md if necessary

Issue

214

Description

Continue (from #235, #236, #237, #329, and #330) to prepare for the new con4m, by no longer running the con4m executable at build time to generate c4autoconf.nim. This was a module that:

• Unloaded attributes into Nim-native data structures.

• Generated Nim-native procs to access that data.

We want to access attributes more directly from the con4m state, which also ensures that attribute access can be multi-threaded. Furthermore, syncing the con4m attribute state with the Nim-native data structures was previously a significant source of complexity.

As of the previous commit (9df364bbd80c, "refactor: remove remaining uses of ChalkConfig"), there was already no remaining usage of autogenerated types or procs.

Closes: https://github.com/crashappsec/chalk/issues/214

---

With this PR:

$ git log -1 --format='%h %s'
b45dafd refactor: remove c4autoconf
$ git grep --ignore-case 'autoconf' | wc -l
0