Convert PUZZLES slice from const to static

Speeds up a clean build by ~10% on my system by moving codegen to the aoc library crate, which can begin as soon as the frontend is complete for all year crates. Previously, codegen occurred when compiling the binary aoc crate, after both the frontend and codegen had finished for all year crates, lengthening the critical path.

Author: ictrobot

crates/aoc/src/puzzles.rs

@@ -20,13 +20,13 @@ macro_rules! matcher {
             $d:literal => $day:ident,
         )*}
     )*) => {
-        /// Constant containing each puzzle solution.
+        /// Slice containing all supported puzzle solutions.
         ///
         /// Each puzzle is represented by a tuple of [`Year`], [`Day`] and [`PuzzleFn`], which takes
         /// a input string and returns the part 1 and 2 solutions as strings, or an [`InputError`].
         ///
         /// Generated from [`all_puzzles!`].
-        pub const PUZZLES: &[(Year, Day, PuzzleFn)] = &[$($(
+        pub static PUZZLES: &[(Year, Day, PuzzleFn)] = &[$($(
             (crate::$year::$day::YEAR, crate::$year::$day::DAY, |input: &str| {
                 let input = strip_final_newline(input);
                 let solution = crate::$year::$day::new(input, InputType::Real)?;