Consider add a linter when there is a header called "accept"

Following up https://github.com/Azure/typespec-azure/issues/2124, to set MIME type they need to add content type header, not add accept header.

Start by reading the linked Azure issue 2124 to understand the MIME-type and header context. Determine the intended linter behavior for an accept header used to set a MIME type; done means the misuse is identified by the linter.

Written by the indexing model from the issue text.