feat(swift): sync highlight queries with upstream

Upstream highlight queries have added support for Swift regex literals.
This change brings that support to nvim-treesitter.

Also includes some minor reordering of modifiers for logical consistency
(no impact on highlighting behavior).

queries/swift/highlights.scm

@@ -34,15 +34,15 @@
   "struct"
   "class"
   "actor"
-  "nonisolated"
   "enum"
   "protocol"
   "extension"
   "indirect"
-  "some"
+  "nonisolated"
   "override"
   "convenience"
   "required"
+  "some"
 ] @keyword
 
 [
@@ -124,6 +124,9 @@
 (boolean_literal) @boolean
 "nil" @variable.builtin
 
+; Regex literals
+(regex_literal) @string.regex
+
 ; Operators
 (custom_operator) @operator
 [