build: generate various resources at build run, not build graph

This is stomping towards minimizing our build.zig dependencies so that
it can be cached more often. Right now, touching almost any file in the
project forces the build.zig to rebuild which is destroying my
productivity.

src/config.zig

@@ -48,7 +48,4 @@ pub const Wasm = if (!builtin.target.cpu.arch.isWasm()) struct {} else @import("
 
 test {
     @import("std").testing.refAllDecls(@This());
-
-    // Vim syntax file, not used at runtime but we want to keep it tested.
-    _ = @import("config/vim.zig");
 }