macosversions: Update max OBS version for macOS 11

OBS Studio 31.1 does not support macOS 11 due to the Qt upgrade from 6.6
to 6.8. Mark the maximum OBS version for macOS 11 as 31.0.

Author: RytoEX

checks/utils/macosversions.py

@@ -35,13 +35,13 @@
     "11": {
         "name": "Big Sur",
         "date": datetime.date(2020, 11, 12),
-        "latest": True
+        "max": "31.0"
     },
     # Old versions of OBS read Big Sur as 10.16, so document it too
     "10.16": {
         "name": "Big Sur",
         "date": datetime.date(2020, 11, 12),
-        "latest": True
+        "max": "31.0"
     },
     "10.15": {
         "name": "Catalina",