Add PS256 and EdDSA signature algorithms to AWX when using OIDC

Logging in using OIDC is successful when RS256 is set on the IDP (keycloak in my case), but unsuccessful when PS256 or EdDSA is set.

Use EdDSA where possible and use ECDSA when it is not. If you are forced to use RSA, prefer RSASSA-PSS [PS256] over RSASSA-PKCS1-v1_5 [RS256] (quoted from “JWTs: Which Signing Algorithm Should I Use?”).