configs: drop unused corebox defconfigs #58

Job	Run time
supervisor (curios-nftables) / build (amd64)	4m 55s
supervisor (curios) / build (amd64)	13m 50s
supervisor (curios-ntpd) / build (amd64)	5m 58s
supervisor (curios-nftables) / build (arm64)	4m 36s
supervisor (curios-httpd) / build (amd64)	4m 48s
supervisor (curios) / build (arm64)	14m 11s
supervisor (curios-ntpd) / build (arm64)	6m 13s
supervisor (curios-httpd) / build (arm64)	4m 35s
supervisor (curios-httpd) / push	12s
supervisor (curios-nftables) / push	21s
supervisor (curios-ntpd) / push	14s
supervisor (curios) / push	31s
	1h 0m 24s

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