Docs: Fix markups for emphasis (pythonGH-135598)

The word emphasis character `_` is not supported as sphinx markup, so changed to `*`.

Author: Yuki Kobayashi

Doc/c-api/refcounting.rst

@@ -210,7 +210,7 @@ of Python objects.
 
         Py_SETREF(dst, src);
 
-   That arranges to set *dst* to *src* _before_ releasing the reference
+   That arranges to set *dst* to *src* *before* releasing the reference
    to the old value of *dst*, so that any code triggered as a side-effect
    of *dst* getting torn down no longer believes *dst* points
    to a valid object.

Doc/library/logging.config.rst

@@ -586,7 +586,7 @@ configuration dictionary for the handler named ``foo``, and later (once that
 handler has been configured) it points to the configured handler instance.
 Thus, ``cfg://handlers.foo`` could resolve to either a dictionary or a handler
 instance. In general, it is wise to name handlers in a way such that dependent
-handlers are configured _after_ any handlers they depend on; that allows
+handlers are configured *after* any handlers they depend on; that allows
 something like ``cfg://handlers.foo`` to be used in configuring a handler that
 depends on handler ``foo``. If that dependent handler were named ``bar``,
 problems would result, because the configuration of ``bar`` would be attempted