Fix robot-server docs build script.

The actual problem was passing an int where a str was expected.

This was failing in a way that was more annoying than necessary to debug because we were only showing the exception message, not the stack trace. Since this is an internal tool for dev and CI consumption, we have no reason to hide stack traces, so this lets the exception propagate and display in the default Python way.

robot-server/scripts/spec_generator.py

@@ -21,7 +21,7 @@
 def write_api_spec(output: TextIOBase) -> None:
     spec_dict = get_openapi(
         title="Opentrons HTTP API Spec",
-        version=API_VERSION,
+        version=str(API_VERSION),
         description=(
             "This OpenAPI spec describes the HTTP API for Opentrons "
             "robots. It may be retrieved from a robot on port 31950 at "
@@ -34,7 +34,7 @@ def write_api_spec(output: TextIOBase) -> None:
     json.dump(spec_dict, output)
 
 
-def _run_cmdline() -> None:
+def _run_cmdline() -> int:
     parser = ArgumentParser(
         description="Generate a static openapi spec. Note: robot-server must be importable when you run this."
     )
@@ -45,12 +45,8 @@ def _run_cmdline() -> None:
         help="Where to write the file (will be json)",
     )
     args = parser.parse_args()
-    try:
-        write_api_spec(args.output)
-        return 0
-    except Exception as e:
-        sys.stderr.write(str(e) + "\n")
-        return -1
+    write_api_spec(args.output)
+    return 0
 
 
 if __name__ == "__main__":