chore: Add @JsonCreator to McpError #173

Job	Run time
Client Conformance (sse-retry)	47s
Client Conformance (elicitation-sep1034-client-defaults)	48s
Client Conformance (initialize)	50s
Server Conformance	47s
Client Conformance (tools_call)	57s
Auth Conformance (auth/metadata-var3)	57s
Auth Conformance (auth/metadata-var1)	48s
Auth Conformance (auth/metadata-var2)	50s
Auth Conformance (auth/scope-from-scopes-supported)	46s
Auth Conformance (auth/basic-cimd)	49s
Auth Conformance (auth/scope-omitted-when-undefined)	44s
Auth Conformance (auth/token-endpoint-auth-none)	44s
Auth Conformance (auth/scope-step-up)	58s
Auth Conformance (auth/scope-from-www-authenticate)	48s
Auth Conformance (auth/scope-retry-limit)	44s
Auth Conformance (auth/metadata-default)	51s
Auth Conformance (auth/token-endpoint-auth-post)	1m 0s
Auth Conformance (auth/pre-registration)	44s
Auth Conformance (auth/token-endpoint-auth-basic)	53s
	15m 45s

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