chore(deps): update dependency com_github_bazelbuild_buildtools to v6.4.0

Author: renovate[bot]

WORKSPACE

@@ -23,10 +23,10 @@ http_archive(
 
 http_archive(
     name = "com_github_bazelbuild_buildtools",
-    sha256 = "ca524d4df8c91838b9e80543832cf54d945e8045f6a2b9db1a1d02eec20e8b8c",
-    strip_prefix = "buildtools-6.0.1",
+    sha256 = "05c3c3602d25aeda1e9dbc91d3b66e624c1f9fdadf273e5480b489e744ca7269",
+    strip_prefix = "buildtools-6.4.0",
     urls = [
-        "https://github.com/bazelbuild/buildtools/archive/refs/tags/6.0.1.tar.gz",
+        "https://github.com/bazelbuild/buildtools/archive/refs/tags/v6.4.0.tar.gz",
     ],
 )