fix dynamically linked devshell

This failed to inherit the fix from bec507d739
because the crane package's buildInputs become propagatedBuildInputs in
a static stdenv, but become normal buildInputs in a dynamic stdenv. Since
we were only pulling propagatedBuildInputs into the devshell, dynamically
linked devshells did not include the rust-jemalloc-sys package. This
causes tikv-jemalloc-sys to build it's own static jemalloc package, and
we end up loading libc before jemalloc at runtime.

flake.nix

@@ -92,6 +92,7 @@
           # Useful for editing the book locally
           mdbook
         ])
+        ++ scope.main.buildInputs
         ++ scope.main.propagatedBuildInputs
         ++ scope.main.nativeBuildInputs;