[3.13] gh-101100: Fix Sphinx warnings in Doc/library/signal.rst (GH-139930) (GH-139967)

gh-101100: Fix Sphinx warnings in `Doc/library/signal.rst` (GH-139930)
(cherry picked from commit 447c7a89fb)

Co-authored-by: Weilin Du <108666168+LamentXU123@users.noreply.github.com>

Doc/library/signal.rst

@@ -270,7 +270,7 @@ The variables defined in the :mod:`signal` module are:
    All the signal numbers are defined symbolically.  For example, the hangup signal
    is defined as :const:`signal.SIGHUP`; the variable names are identical to the
    names used in C programs, as found in ``<signal.h>``.  The Unix man page for
-   ':c:func:`signal`' lists the existing signals (on some systems this is
+   '``signal``' lists the existing signals (on some systems this is
    :manpage:`signal(2)`, on others the list is in :manpage:`signal(7)`). Note that
    not all systems define the same set of signal names; only those names defined by
    the system are defined by this module.
@@ -661,9 +661,8 @@ The :mod:`signal` module defines the following functions:
    *sigset*.
 
    The return value is an object representing the data contained in the
-   :c:type:`siginfo_t` structure, namely: :attr:`si_signo`, :attr:`si_code`,
-   :attr:`si_errno`, :attr:`si_pid`, :attr:`si_uid`, :attr:`si_status`,
-   :attr:`si_band`.
+   ``siginfo_t`` structure, namely: ``si_signo``, ``si_code``,
+   ``si_errno``, ``si_pid``, ``si_uid``, ``si_status``, ``si_band``.
 
    .. availability:: Unix.
 

Doc/tools/.nitignore

@@ -30,7 +30,6 @@ Doc/library/profile.rst
 Doc/library/pyexpat.rst
 Doc/library/resource.rst
 Doc/library/select.rst
-Doc/library/signal.rst
 Doc/library/smtplib.rst
 Doc/library/socket.rst
 Doc/library/ssl.rst