`configparser.RawConfigParser` stub does not account for non-string options

The stub for configparser.RawConfigParser.set has its value argument typed as str | None (source) when it can accept lots of other types and is leading to a false positive in mypy for me.

Consider this valid script:

from configparser import RawConfigParser

cfg = RawConfigParser()
cfg.add_section("default")

cfg.set("default", "some_option1", True)
r1 = cfg.get("default", "some_option1")
print(r1, type(r1))


cfg.set("default", "some_option2", 1)
r2 = cfg.get("default", "some_option2")
print(r2, type(r2))

cfg.set("default", "some_option3", b"bytes")
r3 = cfg.get("default", "some_option3")
print(r3, type(r3))

It prints:

True <class 'bool'>
1 <class 'int'>
b'bytes' <class 'bytes'>

However, mypy flags this code for the reason described above:

test.py:6: error: Argument 3 to "set" of "RawConfigParser" has incompatible type "bool"; expected "Optional[str]"
test.py:11: error: Argument 3 to "set" of "RawConfigParser" has incompatible type "int"; expected "Optional[str]"
test.py:15: error: Argument 3 to "set" of "RawConfigParser" has incompatible type "bytes"; expected "Optional[str]"

从 stdlib/configparser.pyi 第 133 行附近开始，将 RawConfigParser.set 的签名与 issue 中展示的行为进行比较。使用 mypy 运行提供的脚本以复现误报，然后验证 boolean、integer 和 bytes 值能够无错误地被接受，同时现有的 get 行为仍然得到覆盖。