rustPlatform.maturinBuildHook: fix postBuild hook to use ./dist contract

pkgs/build-support/rust/hooks/maturin-build-hook.sh

@@ -24,8 +24,6 @@ maturinBuildHook() {
         ${maturinBuildFlags-}
     )
 
-    runHook postBuild
-
     if [ ! -z "${buildAndTestSubdir-}" ]; then
         popd
     fi
@@ -34,6 +32,9 @@ maturinBuildHook() {
     mkdir -p dist
     mv target/wheels/*.whl dist/
 
+    # These are python build hooks and may depend on ./dist
+    runHook postBuild
+
     echo "Finished maturinBuildHook"
 }