core and langchain: Remove upper bound restriction langsmith dependency (#31629)

Remove upper bound limitation of LS for good measure: we have full
control over LS so we'll be careful when minor bumping so this shouldn't
risk too much, while on the other hand existing such upperboud
restriction will likely introduce occasional dependency headache for
users

Discussion:
https://langchain.slack.com/archives/C06UEEE4DSS/p1750111219634649?thread_ts=1750107647.115289&cid=C06UEEE4DSS

Author: EugeneJinXin

libs/core/pyproject.toml

@@ -7,7 +7,7 @@ authors = []
 license = {text = "MIT"}
 requires-python = ">=3.9"
 dependencies = [
-    "langsmith<0.5,>=0.3.45",
+    "langsmith>=0.3.45",
     "tenacity!=8.4.0,<10.0.0,>=8.1.0",
     "jsonpatch<2.0,>=1.33",
     "PyYAML>=5.3",

libs/core/uv.lock

@@ -9,7 +9,7 @@ requires-python = ">=3.9"
 dependencies = [
     "langchain-core<1.0.0,>=0.3.58",
     "langchain-text-splitters<1.0.0,>=0.3.8",
-    "langsmith<0.5,>=0.1.17",
+    "langsmith>=0.1.17",
     "pydantic<3.0.0,>=2.7.4",
     "SQLAlchemy<3,>=1.4",
     "requests<3,>=2",