[doc] Fix erroneous backslashes in signatures and names (GH-23658)



The issue being resolved is shown in the 3.10 docs (if you select docs for older versions you won't see a visual glitch).

The newer sphinx version that produces the 3.10 docs doesn't treat the backslash to escape things in some situations it previously did.
diff --git a/Doc/library/asyncio-future.rst b/Doc/library/asyncio-future.rst
index e1ac18e..939d4c1 100644
--- a/Doc/library/asyncio-future.rst
+++ b/Doc/library/asyncio-future.rst
@@ -31,7 +31,7 @@
    .. versionadded:: 3.5
 
 
-.. function:: ensure_future(obj, \*, loop=None)
+.. function:: ensure_future(obj, *, loop=None)
 
    Return:
 
@@ -58,7 +58,7 @@
       The function accepts any :term:`awaitable` object.
 
 
-.. function:: wrap_future(future, \*, loop=None)
+.. function:: wrap_future(future, *, loop=None)
 
    Wrap a :class:`concurrent.futures.Future` object in a
    :class:`asyncio.Future` object.
@@ -67,7 +67,7 @@
 Future Object
 =============
 
-.. class:: Future(\*, loop=None)
+.. class:: Future(*, loop=None)
 
    A Future represents an eventual result of an asynchronous
    operation.  Not thread-safe.