PEP 725: Fix Sphinx reference warning (#4440)

Author: hugovk

peps/pep-0725.rst

@@ -663,9 +663,9 @@ References
 .. [#pypackaging-native-cross] pypackaging-native: "Cross compilation"
    https://pypackaging-native.github.io/key-issues/cross_compilation/
 
-.. [#pkgconfig-and-ctypes-findlibrary] The "``pkgconfig`` specification as an
-   alternative to ``ctypes.util.find_library``" thread (2023, Discourse):
-   https://discuss.python.org/t/pkgconfig-specification-as-an-alternative-to-ctypes-util-find-library/31379
+* The "``pkgconfig`` specification as an
+  alternative to ``ctypes.util.find_library``" thread (2023, Discourse):
+  https://discuss.python.org/t/pkgconfig-specification-as-an-alternative-to-ctypes-util-find-library/31379
 
 
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