Modifying the content-type header breaks some integrations

[viniciuspinto]

The line [1] adds the charset to the Content-Type header and this breaks the integration with some services. In my tests, calling a Bedrock model was returning "The provided Content Type is invalid or nor supported for this model". After removing the line, the issue was gone.

[1] https://github.com/tedder/requests-aws4auth/blob/9e9e7bf25ad1962cd8dd77064216ee4cab8ca520/requests_aws4auth/aws4auth.py#L563C57-L563C72

[tedder]

Hmm, if you remove it and submit a PR, do all the unit tests pass?