Friendlier error message than `FileNotFoundError`

[iaindillingham]

If the input file doesn't exist, then SQL Runner prints a stack trace. A friendlier error message than FileNotFoundError would be nice.

Running actions: query

jobrunner.run loop started
query: Copying in code from /Users/iaindillingham/Code/opensafely/tpp-database-schema
query: Preparing
query: Executing
query: Logs written to: /Users/iaindillingham/Code/opensafely/tpp-database-schema/metadata/query.log
query: Finalizing
query: Job exited with error code 1
query: Cleaning up container and volume

=> query
   Job exited with error code 1

   log file: metadata/query.log
   outputs:
     (no outputs)

   logs:

     Traceback (most recent call last):
       File "/usr/lib/python3.10/runpy.py", line 196, in _run_module_as_main
         return _run_code(code, main_globals, None,
       File "/usr/lib/python3.10/runpy.py", line 86, in _run_code
         exec(code, run_globals)
       File "/app/sqlrunner/__main__.py", line 8, in <module>
         sql_query = main.read_text(args.input)
       File "/app/sqlrunner/main.py", line 37, in read_text
         return f_path.read_text(encoding="utf-8")
       File "/usr/lib/python3.10/pathlib.py", line 1134, in read_text
         with self.open(mode='r', encoding=encoding, errors=errors) as f:
       File "/usr/lib/python3.10/pathlib.py", line 1119, in open
         return self._accessor.open(self, mode, buffering, encoding, errors,
     FileNotFoundError: [Errno 2] No such file or directory: 'analysis/query.sql'