refactor: remove c4autoconf

[ee7]

• Followed the steps in the contributor's guide: https://crashoverride.com/docs/other/contributing#filing-the-pull-request
• PR title uses semantic commit messages
• Filled out the template to a useful degree
• 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 (9df364b, "refactor: remove remaining uses of ChalkConfig"), there was already no remaining usage of autogenerated types or procs.

Closes: #214

---

With this PR:

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