Remove experimental flag for logs options

[AbhiPrasad]

Instead of

sentry_sdk.init(
    dsn=MY_DSN,
    _experiments={
        "enable_logs": True,
        "before_send_log": before_send_log
    },
)

we do

sentry_sdk.init(
    dsn=MY_DSN,
    "enable_logs": True,
    "before_send_log": before_send_log
)

Ideally this is done in a backwards compatible way, so that in v2 of python we support both the top level enable_logs and _experiments["enable_logs"] options, but in v3 we only support enable_logs.

[linear]

PY-1791 Remove experimental flag for logs options