[ci] Fix shebangs

nix/frama-c.nix

@@ -71,7 +71,7 @@ stdenv.mkDerivation rec {
 
   buildPhase = ''
     make config.sed
-    dune build -j2 --display short @install
+    dune build --display short @install
   '';
 
   installFlags = [

nix/main-tests.nix

@@ -22,6 +22,10 @@ stdenv.mkDerivation rec {
     which
   ];
 
+  postPatch = ''
+    patchShebangs .
+  '' ;
+
   # Keep main configuration
   configurePhase = ''
     true
@@ -31,7 +35,7 @@ stdenv.mkDerivation rec {
     make ptests/ptests.exe
     make ptests/wtests.exe
     dune exec --root ptests -- frama-c-ptests tests
-    dune build -j1 --display short @tests/ptests
+    dune build --display short @tests/ptests
   '';
 
   # No installation required

nix/plugins-tests.nix

@@ -26,6 +26,10 @@ stdenv.mkDerivation rec {
     which
   ];
 
+  postPatch = ''
+    patchShebangs .
+  '' ;
+
   # Keep main configuration
   # Only for WP qualif -> replace with true after split
   configurePhase = ''