Prevent installation of MagicPython on ST4

There is very little reason to do this when the default syntax
definition is much better due to using the `sublime-syntax` format,
follows the scope naming standards and is actively maintained, because
this package hasn't had a tag pushed in 4 years despite seeing *some*
changes, albeit the last one over a year ago.

A pull request asking for clarification of the support status for ST4
has not been answered for 8 months.
MagicStack/MagicPython#255

repository/m.json

@@ -185,7 +185,7 @@
 			"labels": ["language syntax", "python"],
 			"releases": [
 				{
-					"sublime_text": "*",
+					"sublime_text": "<4000",
 					"tags": true
 				}
 			]