oeqa: replace deprecated assertEquals

assertEquals is deprecated since Python 2.7:
https://docs.python.org/2/library/unittest.html#deprecated-aliases
It throws errors at least on Python 3.12. Replace it by assertEqual.

(From OE-Core rev: 68286d0b70cf09a0d2950b48945c9192fb8c8769)

Signed-off-by: Adrian Freihofer <adrian.freihofer@siemens.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/selftest/cases/devtool.py

@@ -1097,7 +1097,7 @@ class DevtoolModifyTests(DevtoolBase):
             runCmd('git -C %s checkout %s' % (tempdir, branch))
             with open(source, "rt") as f:
                 content = f.read()
-            self.assertEquals(content, expected)
+            self.assertEqual(content, expected)
         if self.td["MACHINE"] == "qemux86":
             check('devtool', 'This is a test for qemux86\n')
         elif self.td["MACHINE"] == "qemuarm":