[tests] Try and fix tests on Fedora Linux

tests/verify_json.t

@@ -14,7 +14,7 @@ Test verify-json
 
   $ PATH=$(pwd)/bin:$PATH
 
-  $ caisar verify-json --ltag=ProverSpec config.json 2>&1 <<EOF | ./filter_tmpdir.sh
+  $ caisar verify-json --ltag=ProverSpec config.json 2>&1 | ./filter_tmpdir.sh
   [DEBUG]{ProverSpec} Prover-tailored specification:
   ;;; produced by PyRAT/VNN-LIB driver
   ;;; produced by VNN-LIB driver

tests/xgboost.t

 Test verify
   $ PATH=$(pwd)/bin:$PATH
 
-  $ caisar verify-xgboost ../lib/xgboost/example/california.json ../lib/xgboost/example/california.csv --prover CVC5 2>&1 <<EOF | ./filter_tmpdir.sh
+  $ caisar verify-xgboost ../lib/xgboost/example/california.json ../lib/xgboost/example/california.csv --prover CVC5 2>&1 | ./filter_tmpdir.sh
   result: Unknown
   (unknown)