Things to check first

• I have searched the existing issues and didn't find my bug already reported there

• I have checked that my bug is still present in the latest release

cbor2 version

5.6.5

Python version

Python 3.10.14

What happened?

The str_errors kwarg is no longer working as expected since 5.6.0:
When passing str_errors="replace", bytes that failed to decode, should be replaced with a replacement character. Instead, CBORDecodeValueError is always raised.

How can we reproduce the bug?

Before 5.6.0 (e.g. 5.5.1):

>>> cbor2.loads(b"cfo\x90", str_errors="replace")
'fo�'

Since 5.6.0:

>>> cbor2.loads(b"cfo\x90", str_errors="replace")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x90 in position 2: invalid start byte

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
_cbor2.CBORDecodeValueError: error decoding unicode string