Make TC_POOLING_INTERVAL/sleep_time a float

This config variable gets passed into `time.sleep`, which can work with ints and floats. Making this a float type allows polling intervals under a second, which can reduce startup times for containers that spin up very quickly.

Author: samuelhwilliams

core/testcontainers/core/config.py

@@ -97,7 +97,7 @@ def read_tc_properties() -> dict[str, str]:
 @dataclass
 class TestcontainersConfiguration:
     max_tries: int = int(environ.get("TC_MAX_TRIES", "120"))
-    sleep_time: int = int(environ.get("TC_POOLING_INTERVAL", "1"))
+    sleep_time: float = float(environ.get("TC_POOLING_INTERVAL", "1"))
     ryuk_image: str = environ.get("RYUK_CONTAINER_IMAGE", "testcontainers/ryuk:0.8.1")
     ryuk_privileged: bool = get_bool_env("TESTCONTAINERS_RYUK_PRIVILEGED")
     ryuk_disabled: bool = get_bool_env("TESTCONTAINERS_RYUK_DISABLED")