Deprecated unittest aliases were removed in Python 3.11

[tirkarthi]

python/cpython#28268

nose2pytest/nose2pytest/assert_tools.py

Line 88 in 758b27a

assert_raises_regexp=_t.assertRaisesRegexp,

nose2pytest/nose2pytest/assert_tools.py

Line 89 in 758b27a

assert_regexp_matches=_t.assertRegexpMatches,

Since the library is Python 3.5 + the recommended aliases can be used

assertRaisesRegexp -> assertRaisesRegex
assertRegexpMatches -> assertRegex