core[patch]: remove requests (#19891)

Removes required usage of `requests` from `langchain-core`, all of which
has been deprecated.

- removes Tracer V1 implementations
- removes old `try_load_from_hub` github-based hub implementations

Removal done in a way where imports will still succeed, and usage will
fail with a `RuntimeError`.

libs/experimental/langchain_experimental/prompts/load.py

@@ -1,52 +1,3 @@
-# Susceptible to arbitrary code execution: https://github.com/langchain-ai/langchain/issues/4849
-import importlib.util
-import json
-from pathlib import Path
-from typing import Union
+from langchain.prompts.loading import load_prompt
 
-import yaml
-from langchain.prompts.loading import load_prompt_from_config, try_load_from_hub
-from langchain_core.prompts import BasePromptTemplate
-
-
-def load_prompt(path: Union[str, Path]) -> BasePromptTemplate:
-    """Unified method for loading a prompt from LangChainHub or local file system."""
-
-    if hub_result := try_load_from_hub(
-        path, _load_prompt_from_file, "prompts", {"py", "json", "yaml"}
-    ):
-        return hub_result
-    else:
-        return _load_prompt_from_file(path)
-
-
-def _load_prompt_from_file(file: Union[str, Path]) -> BasePromptTemplate:
-    """Load prompt from file."""
-    # Convert file to a Path object.
-    if isinstance(file, str):
-        file_path = Path(file)
-    else:
-        file_path = file
-    # Load from either json or yaml.
-    if file_path.suffix == ".json":
-        with open(file_path) as f:
-            config = json.load(f)
-    elif file_path.suffix.endswith((".yaml", ".yml")):
-        with open(file_path, "r") as f:
-            config = yaml.safe_load(f)
-    elif file_path.suffix == ".py":
-        spec = importlib.util.spec_from_loader(
-            "prompt", loader=None, origin=str(file_path)
-        )
-        if spec is None:
-            raise ValueError("could not load spec")
-        helper = importlib.util.module_from_spec(spec)
-        with open(file_path, "rb") as f:
-            exec(f.read(), helper.__dict__)
-        if not isinstance(helper.PROMPT, BasePromptTemplate):
-            raise ValueError("Did not get object of type BasePromptTemplate.")
-        return helper.PROMPT
-    else:
-        raise ValueError(f"Got unsupported file type {file_path.suffix}")
-    # Load the prompt from the config now.
-    return load_prompt_from_config(config)
+__all__ = ["load_prompt"]