feat(backend): replace Selenium with Playwright

BREAKING CHANGE: backend now requires Python 3.12 or newer.

pyproject.toml

@@ -3,7 +3,7 @@ name = "checkin-app-backend"
 version = "0.1.0"
 description = "FastAPI backend for CheckIn App"
 readme = "README.md"
-requires-python = ">=3.9"
+requires-python = ">=3.12"
 dependencies = [
     "apscheduler>=3.10.4",
     "bcrypt>=4.2.2",
@@ -15,7 +15,7 @@ dependencies = [
     "pyjwt>=2.10.1",
     "python-dotenv>=1.0.1",
     "requests>=2.32.3",
-    "selenium>=4.28.1",
+    "playwright>=1.50.0",
     "slowapi>=0.1.9",
     "sqlalchemy>=2.0.36",
     "uvicorn[standard]>=0.34.0",
@@ -48,7 +48,7 @@ namespaces = true
 
 [tool.ruff]
 line-length = 100
-target-version = "py39"
+target-version = "py312"
 src = ["apps", "tests"]
 
 [tool.ruff.lint]