openmpi: remove env.SOURCE_DATE_EPOCH

-1
-1
pkgs/by-name/op/openmpi/package.nix
··· 70 env = { 71 USER = "nixbld"; 72 HOSTNAME = "localhost"; 73 - SOURCE_DATE_EPOCH = "0"; 74 }; 75 76 outputs = [
··· 70 env = { 71 USER = "nixbld"; 72 HOSTNAME = "localhost"; 73 }; 74 75 outputs = [