[1.12 regression] New error on type[memoryView] | type[str] #17942

Bug Report

new to 1.12.0
incorrect error message on union of two type one being memoryview

Complete file checked:

"""
a_type: type[memoryview] | type[str] = memoryview
"""

mypy 1.11.2 no error

mypy 1.12.0
Incompatible default for argument "a_type" (default has type "type[memoryview[Any]]", argument has type "type[memoryview[int]] | type[str]")

Your Environment
github action ubuntu various , python various

• Mypy command-line flags:
  -no flags
• Mypy configuration options from mypy.ini (and other config files):
• None
• Python version used: via github actions
  3.8, 3.9, 3.10, 3.11, 3.12 and 3.13

while
"""
a_type: type[memoryview] = memoryview
""""
Works ok!