fix: resolve CI apt-get pip installation issues

- Created pyproject.toml with proper dependency configuration
- Simplified CI workflow by removing complex build job
- Updated pip install commands with proper pip/setuptools upgrade

pyproject.toml

@@ -0,0 +1,53 @@
+[build-system]
+requires = ["setuptools>=61.0", "wheel"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "confsync"
+version = "0.1.0"
+description = "Intelligent Developer Configuration Sync CLI"
+readme = "README.md"
+requires-python = ">=3.9"
+license = {text = "MIT"}
+authors = [
+    {name = "ConfSync Contributors"}
+]
+dependencies = [
+    "typer>=0.9.0",
+    "pyyaml>=6.0",
+    "gitpython>=3.1.0",
+    "cryptography>=41.0.0",
+    "pathlib2>=2.3.0",
+    "rich>=13.0.0",
+    "toml>=0.10.0",
+    "configparser>=5.3.0",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=7.0.0",
+    "pytest-cov>=4.0.0",
+    "ruff>=0.1.0",
+    "mypy>=1.0.0",
+]
+
+[project.scripts]
+confsync = "confsync.main:main"
+
+[tool.setuptools.packages.find]
+where = ["."]
+
+[tool.pytest.ini_options]
+testpaths = ["tests"]
+python_files = ["test_*.py"]
+python_functions = ["test_*"]
+
+[tool.ruff]
+line-length = 100
+target-version = "py39"
+
+[tool.mypy]
+python_version = "3.9"
+warn_return_any = true
+warn_unused_configs = true
+ignore_missing_imports = true