test: remove usage of deprecated method `TestCase.assertEquals` (#1494)

`TestCase.assertEquals` is an alias for `TestCase.assertEqual`.
[This method is deprecated since Python 3.2 and was removed in Python
3.12](https://docs.python.org/3/whatsnew/3.12.html#id3).
diff --git a/examples/bzlmod/test.py b/examples/bzlmod/test.py
index 80cd027..5331875 100644
--- a/examples/bzlmod/test.py
+++ b/examples/bzlmod/test.py
@@ -76,7 +76,7 @@
             )
 
     def test_main(self):
-        self.assertEquals(
+        self.assertEqual(
             """\
 -  -
 A  1
diff --git a/examples/bzlmod_build_file_generation/__test__.py b/examples/bzlmod_build_file_generation/__test__.py
index cdc1c89..cde1d42 100644
--- a/examples/bzlmod_build_file_generation/__test__.py
+++ b/examples/bzlmod_build_file_generation/__test__.py
@@ -19,7 +19,7 @@
 
 class ExampleTest(unittest.TestCase):
     def test_main(self):
-        self.assertEquals(
+        self.assertEqual(
             """\
 -  -
 A  1
diff --git a/examples/wheel/wheel_test.py b/examples/wheel/wheel_test.py
index ab7b59d..43fbe0c 100644
--- a/examples/wheel/wheel_test.py
+++ b/examples/wheel/wheel_test.py
@@ -198,7 +198,7 @@
         )
         with zipfile.ZipFile(filename) as zf:
             self.assertAllEntriesHasReproducibleMetadata(zf)
-            self.assertEquals(
+            self.assertEqual(
                 zf.namelist(),
                 [
                     "examples/wheel/lib/data.txt",
@@ -216,7 +216,7 @@
             metadata_contents = zf.read(
                 "file_name_escaping-0.0.1_r7.dist-info/METADATA"
             )
-            self.assertEquals(
+            self.assertEqual(
                 metadata_contents,
                 b"""\
 Metadata-Version: 2.1