fix: change request objects typ to oauth-authz-req+jwt

[nanderstabel]

Description of change

Updates the request object typ header field to oauth-authz-req+jwt.

As described here: https://www.rfc-editor.org/rfc/rfc9101.html#section-10.8-3

Links to any relevant issues

n/a

How the change has been tested

n/a

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