chore(core): Remove python-dotenv (#2721)

# Description

Closes #2714

# How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide
instructions so we can reproduce. Please also list any relevant details
for your test configuration

# Snapshots:

Include snapshots for easier review.

# Checklist:

- [x] My code follows the style guidelines of this project
- [x] I have already rebased the commits and make the commit message
conform to the project standard.
- [x] I have performed a self-review of my own code
- [x] I have commented my code, particularly in hard-to-understand areas
- [x] I have made corresponding changes to the documentation
- [x] Any dependent changes have been merged and published in downstream
modules

packages/dbgpt-core/pyproject.toml

@@ -15,7 +15,6 @@ dependencies = [
     "aiohttp==3.8.4",
     "chardet==5.1.0",
     "importlib-resources==5.12.0",
-    "python-dotenv==1.0.0",
     "cachetools",
     "pydantic>=2.6.0",
     # For AWEL type checking

packages/dbgpt-core/src/dbgpt/configs/__init__.py

@@ -4,18 +4,12 @@ import os
 import random
 import sys
 
-from dotenv import load_dotenv
-
 if "pytest" in sys.argv or "pytest" in sys.modules or os.getenv("CI"):
     print("Setting random seed to 42")
     random.seed(42)
 
-# Load the users .env file into environment variables
-# load_dotenv(verbose=True, override=True)
 ROOT_PATH = os.path.dirname(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
-# load_dotenv(os.path.join(ROOT_PATH, ".plugin_env"))
 
-del load_dotenv
 
 TAG_KEY_KNOWLEDGE_FACTORY_DOMAIN_TYPE = "knowledge_factory_domain_type"
 TAG_KEY_KNOWLEDGE_CHAT_DOMAIN_TYPE = "knowledge_chat_domain_type"