Fixes recursion bug related to enum flags

[matt035343]

Fixes #445

[github-actions[bot]]

Coverage Report

File	Stmts	Miss	Cover	Missing
dataclasses_json
cfg.py	51	4	92%	80, 84–86
core.py	234	9	96%	38–41, 51, 64, 66, 81, 83, 169
mm.py	199	29	85%	33–36, 42–45, 53–56, 62–65, 88, 161–162, 167, 171, 175, 180, 184, 188, 196, 202, 207, 216, 221, 226, 244–251
stringcase.py	25	3	88%	59, 76, 97
undefined.py	143	2	99%	24, 38
utils.py	128	29	77%	11–24, 44–49, 60–64, 74, 99–100, 108–109, 158, 177, 202
tests
entities.py	220	2	99%	229, 235
test_annotations.py	81	42	48%	50–67, 78–102, 106–122
test_api.py	142	2	99%	139–140
test_str_subclass.py	22	1	95%	9
TOTAL	2474	123	95%

Tests	Skipped	Failures	Errors	Time
291	1 :zzz:	0 :x:	0 :fire:	4.506s :stopwatch:

[george-zubrienko]

@powellnorma please take a look as well :)

[powellnorma]

Looks good to me