[test] Fix tests after PEP 625

Adapt tests to ignore warning generated by setuptools not finding
zc.recipe.egg on first index lookup, because it's indexed as
zc-recipe-egg, because since PEP 625 the sdist filename is
zc_recipe_egg-xyz.tar.gz.

src/zc/buildout/tests/test_all.py

@@ -4045,6 +4045,13 @@ def test_suite():
                     zc.buildout.testing.normalize_egg_py,
                     zc.buildout.testing.not_found,
                     zc.buildout.testing.root_logger_messages,
+                    # Needed during zc.recipe.egg lookup since PEP 625,
+                    # because setup.py sdist generates zc_recipe_egg-xyz.tar.gz
+                    # in the test index and setuptools then finds zc-recipe-egg
+                    # in the index instead of zc.recipe.egg.
+                    (re.compile(
+                      r"Couldn't find index page for 'zc.recipe.egg' "
+                      r"\(maybe misspelled\?\)\r?\n"), ''),
                     # Needed for a test that changes log format
                     (re.compile(r'^(WARNING )+', re.MULTILINE), ''),
                     zc.buildout.testing.adding_find_link,