chore: rewrite devshell, remove checks

nix/crane.nix

@@ -0,0 +1,14 @@
+{ inputs, ... }:
+{
+  perSystem =
+    {
+      pkgs,
+      self',
+      ...
+    }:
+    {
+      _module.args.craneLib = (inputs.crane.mkLib pkgs).overrideToolchain (
+        pkgs: self'.packages.stable-toolchain
+      );
+    };
+}