fix(core): serialization patch (#34455)

- `allowed_objects` kwarg in `load`
- escape lc-ser formatted dicts on `dump`
- fix for jinja2

---------

Co-authored-by: Mason Daugherty <github@mdrxy.com>

libs/partners/xai/uv.lock

@@ -1,5 +1,5 @@
 version = 1
-revision = 2
+revision = 3
 requires-python = ">=3.10.0, <4.0.0"
 resolution-markers = [
     "python_full_version >= '3.13' and platform_python_implementation == 'PyPy'",
@@ -621,7 +621,7 @@ wheels = [
 
 [[package]]
 name = "langchain-core"
-version = "1.2.3"
+version = "1.2.4"
 source = { editable = "../../core" }
 dependencies = [
     { name = "jsonpatch" },