fix pr exclusions on hydra

Author: cleverca22

release.nix

@@ -9,14 +9,15 @@
 
 # The project sources
 { cardano-node ? { outPath = ./.; rev = "abcdef"; }
+, pr ? null
 }:
 
 let
   inherit (import ./nix/flake-compat.nix {
     src = cardano-node;
   }) defaultNix;
 
-  jobs = defaultNix.hydraJobs;
+  jobs = if (pr == null) then defaultNix.hydraJobs else defaultNix.hydraJobsPr;
 
 in
 jobs