Unset loglevel in amici.sim.sundials._swig_wrappers

This way, that logger will inherit the log level from its parents,
and users can set the log level with, e.g.,
`logging.getLogger("amici.sim.sundials").setLevel(logging.CRITICAL)`
without exposing any private modules.

Related to #3081.
`

Author: dweindl

python/sdist/amici/logging.py

@@ -79,7 +79,8 @@ def _setup_logger(
                     f" (case-sensitive) or an integer log level."
                 )
 
-    log.setLevel(level)
+    if level is not None:
+        log.setLevel(level)
 
     py_warn_logger = logging.getLogger("py.warnings")
 
@@ -118,7 +119,9 @@ def _setup_logger(
     return log
 
 
-def set_log_level(logger: logging.Logger, log_level: int | bool) -> None:
+def set_log_level(
+    logger: logging.Logger, log_level: int | bool | None
+) -> None:
     if log_level is not None and log_level is not False:
         if isinstance(log_level, bool):
             log_level = logging.DEBUG

python/sdist/amici/sim/sundials/_swig_wrappers.py

@@ -30,7 +30,7 @@
 
 from . import ReturnDataView
 
-logger = get_logger(__name__, log_level=logging.DEBUG)
+logger = get_logger(__name__, log_level=None)
 
 
 __all__ = [