feat(server)!: oauth encryption algorithm setting (#6818)

* feat: add oauth signing algorithm setting

* chore: open api

* chore: change default to RS256

* feat: test and clean up

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Co-authored-by: Jason Rasmussen <jrasm91@gmail.com>

server/src/domain/system-config/system-config.service.spec.ts

@@ -98,6 +98,7 @@ const updatedConfig = Object.freeze<SystemConfig>({
     mobileOverrideEnabled: false,
     mobileRedirectUri: '',
     scope: 'openid email profile',
+    signingAlgorithm: 'RS256',
     storageLabelClaim: 'preferred_username',
   },
   passwordLogin: {