mypy warns about invalid types for json argument

I have warnings about invalid types for the json argument, that didn't occur when using types-requests.

The changes in v2.34.1 changed the errors, but did not fix them.

typecheck.py:6: error: Argument "json" to "post" has incompatible type "dict[str, Collection[str]]"; expected "JsonType"  [arg-type]
typecheck.py:9: error: Argument "json" to "post" has incompatible type "dict[str, object]"; expected "JsonType"  [arg-type]

Reproduction Steps

import requests

def fn(d: dict[str, str]) -> None:
    j = {"foo": d, "bar": "hi"}
    requests.post("https://example.com", json=j)

    k = {"foo": d, "bool": True}
    requests.post("https://example.com", json=k)

It seems ok if a literal is used without the intermediate variable:

    requests.post("https://example.com", json={"foo": d, "bar": "hi"})
    requests.post("https://example.com", json={"foo": d, "bool": True})

System Information

{
  "chardet": {
    "version": null
  },
  "charset_normalizer": {
    "version": "3.4.7"
  },
  "cryptography": {
    "version": ""
  },
  "idna": {
    "version": "3.15"
  },
  "implementation": {
    "name": "CPython",
    "version": "3.13.5"
  },
  "platform": {
    "release": "6.12.74+deb13+1-amd64",
    "system": "Linux"
  },
  "pyOpenSSL": {
    "openssl_version": "",
    "version": null
  },
  "requests": {
    "version": "2.34.1"
  },
  "system_ssl": {
    "version": "30500050"
  },
  "urllib3": {
    "version": "2.7.0"
  },
  "using_charset_normalizer": true,
  "using_pyopenssl": false
}

Start by running mypy against the provided typecheck.py reproduction, focusing on the json argument to requests.post and the difference between intermediate dictionaries and literals. Trace the typing used for that entry point; done means both intermediate-variable examples type-check without invalid-type warnings while the existing literal cases continue to work.