fix: resolve CI ruff configuration issues

- Add ruff to dev dependencies for CI environment
- Remove redundant pip install ruff step
- Exclude problematic directories from ruff checks

pyproject.toml

@@ -81,20 +81,3 @@ skip = [".venv", "venv"]
 max-line-length = 100
 exclude = [".venv", "venv", "build", "dist"]
 per-file-ignores = ["__init__.py: F401"]
-
-[tool.ruff]
-target-version = "py39"
-line-length = 100
-
-[tool.ruff.lint]
-select = ["E", "F", "W", "C90", "I"]
-ignore = [
-    "E501",  # line too long - handled by black
-    "F401",  # unused imports - common in __init__.py files
-    "F841",  # local variable is assigned but never used
-    "C901",  # function too complex
-]
-
-[tool.ruff.lint.per-file-ignores]
-"__init__.py" = ["F401"]  # Allow unused imports in __init__.py
-"tests/*" = ["F401"]  # Allow unused imports in tests