Fix broken links in docs (#35582)

lib/spack/docs/build_systems/pythonpackage.rst

@@ -366,7 +366,7 @@ If the ``pyproject.toml`` lists ``mesonpy`` as the ``build-backend``,
 it uses the meson build system. Meson uses the default
 ``pyproject.toml`` keys to list dependencies.
 
-See https://meson-python.readthedocs.io/en/latest/usage/start.html
+See https://meson-python.readthedocs.io/en/latest/tutorials/introduction.html
 for more information.
 
 """

lib/spack/docs/build_systems/wafpackage.rst

@@ -58,9 +58,7 @@ Testing
 ``WafPackage`` also provides ``test`` and ``installtest`` methods,
 which are run after the ``build`` and ``install`` phases, respectively.
 By default, these phases do nothing, but you can override them to
-run package-specific unit tests. For example, the
-`py-py2cairo <https://github.com/spack/spack/blob/develop/var/spack/repos/builtin/packages/py-py2cairo/package.py>`_
-package uses:
+run package-specific unit tests.
 
 .. code-block:: python