chore: parallel compile fix

packages/leann-backend-diskann/pyproject.toml

@@ -16,4 +16,4 @@ wheel.packages = ["leann_backend_diskann"]
 editable.mode = "redirect"
 cmake.build-type = "Release"
 build.verbose = true
-cmake.build-args = ["-j"]
+build.tool-args = ["-j8"]

packages/leann-backend-hnsw/pyproject.toml

@@ -15,4 +15,4 @@ wheel.packages = ["leann_backend_hnsw"]
 editable.mode = "redirect"
 cmake.build-type = "Release"
 build.verbose = true
-cmake.build-args = ["-j"]
+build.tool-args = ["-j8"]