update resolution to dpi

Author: bprobert97

scripts/glasgow_zenith.py

@@ -80,7 +80,7 @@ def make_zenith_plot(
 
     # Export to in-memory buffer
     buf = io.BytesIO()
-    p.export(buf, format="png", resolution=resolution)
+    p.export(buf, format="png", dpi=resolution)
     buf.seek(0)
 
     return buf.getvalue()