fix: display errors when schema validation fails

Author: chronicc

.config/dictionary.txt

@@ -108,7 +108,6 @@ passwordless
 prepender
 prerun
 profisioner
-psql
 pycolors
 reget
 resetall

src/molecule/config.py

@@ -751,7 +751,8 @@ def _validate(self) -> None:
 
         errors = schema_v3.validate(self.config)
         if errors:
-            msg = f"Failed to validate {self.molecule_file}\n\n{errors}"
+            errors_resolved = "\n".join(errors)
+            msg = f"Failed to validate {self.molecule_file}\n\n{errors_resolved}"
             sysexit_with_message(msg, code=1)