feat(profiling): Allow profiling sample rate to be passed from env (#24)

* feat(profiling): Allow profiling sample rate to be passed from env

This sets a default profiling sample rate of 0 since not everyone may want profiling in CI due to cost concerns, but allows it to be enabled by passing it from the environment.

* Should be a float

pytest_sentry.py

@@ -86,6 +86,7 @@ def __init__(self, *args, **kwargs):
             "traces_sample_rate",
             float(os.environ.get("PYTEST_SENTRY_TRACES_SAMPLE_RATE", 1.0)),
         )
+        kwargs.setdefault("profiles_sample_rate", float(os.environ.get("PYTEST_SENTRY_PROFILES_SAMPLE_RATE", 0.0)))
         kwargs.setdefault("_experiments", {}).setdefault(
             "auto_enabling_integrations", True
         )