add patch for Python syntax to help improve performance

CHANGELOG.md

@@ -5,6 +5,7 @@
 
 ## Bugfixes
 
+- Python syntax highlighting no longer suffers from abysmal performance in specific scenarios. See #1688 (@keith-hall)
 
 ## Other
 

assets/patches/Python.sublime-syntax.patch

@@ -0,0 +1,15 @@
+diff --git syntaxes/01_Packages/Python/Python.sublime-syntax syntaxes/01_Packages/Python/Python.sublime-syntax
+index 2acd86d8..86257f7b 100644
+--- syntaxes/01_Packages/Python/Python.sublime-syntax
++++ syntaxes/01_Packages/Python/Python.sublime-syntax
+@@ -988,10 +988,6 @@ contexts:
+         - match: \}
+           scope: punctuation.section.mapping-or-set.end.python
+           set: after-expression
+-        - match: (?={{simple_expression}}:|\s*\*\*)
+-          set: inside-dictionary
+-        - match: (?={{simple_expression}}[,}]|\s*\*)
+-          set: inside-set
+         - match: ','
+           scope: punctuation.separator.set.python
+           set: inside-set