fix: sbatch stderr parsing #2 (#165)

next attempt to fix the behaviour described in #161 

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **Bug Fixes**
- Improved error handling for SLURM job submissions, providing clearer
indications of submission failures.
- Enhanced error reporting with detailed messages for job submission
failures.

- **Chores**
	- Minor adjustments to comments and formatting for better clarity.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Filipe G. Vieira <1151762+fgvieira@users.noreply.github.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

Author: 3 people

snakemake_executor_plugin_slurm/__init__.py

@@ -231,9 +231,10 @@ def run_job(self, job: JobExecutorInterface):
                 )
         except subprocess.CalledProcessError as e:
             raise WorkflowError(
-                f"SLURM job submission failed. The error message was {e.output}"
+                f"SLURM sbatch failed. The error message was {e.output}"
             )
-        if err:  # any other error message?
+        # any other error message indicating failure?
+        if "submission failed" in err:
             raise WorkflowError(
                 f"SLURM job submission failed. The error message was {err}"
             )