docs(init): Fix sentry_sdk.init type hint

The current type hint suggests that all the parameters can be passed as positional arguments, when this is not the case. Only the `dsn` can be passed as a positional argument; the rest must be passed as keyword arguments.

This PR makes the type hint reflect the reality of what parameters can be passed to `sentry_sdk.init`.

Author: szokeasaurusrex

sentry_sdk/consts.py

@@ -479,6 +479,7 @@ class ClientConstructor:
     def __init__(
         self,
         dsn=None,  # type: Optional[str]
+        *,
         max_breadcrumbs=DEFAULT_MAX_BREADCRUMBS,  # type: int
         release=None,  # type: Optional[str]
         environment=None,  # type: Optional[str]
@@ -540,7 +541,7 @@ def __init__(
 
 
 def _get_default_options():
-    # type: () -> Dict[str, Any]
+    # type: () -> dict[str, Any]
     import inspect
 
     if hasattr(inspect, "getfullargspec"):
@@ -549,8 +550,11 @@ def _get_default_options():
         getargspec = inspect.getargspec  # type: ignore
 
     a = getargspec(ClientConstructor.__init__)
-    defaults = a.defaults or ()
-    return dict(zip(a.args[-len(defaults) :], defaults))
+
+    # The logic below relies on all parameters having a default value.
+    # We would need to update the behavior if we ever introduce an
+    # argument without a default value.
+    return dict(a.defaults.items() | a.kwonlydefaults.items())
 
 
 DEFAULT_OPTIONS = _get_default_options()