fix(julia): treat :: as operator in type contexts

This patch captures `::` as `@operator` within
`(unary_typed_expression)` and `(typed_expression)`. These should be the
only two cases that the parser can emit when encountering `::` in the
source, but as a fallback it is still captured as `@punctuation` in all
other cases.

The reasons for capturing `::` as an operator are i) the close relation
with the other type-operators `<:` and `>:` and ii) the fact that it is
treated as an operator by the Julia parser, just like `<:` and `>:`.

queries/julia/highlights.scm

@@ -281,6 +281,14 @@
   "::"
 ] @punctuation.delimiter
 
+; Treat `::` as operator in type contexts, see
+; https://github.com/nvim-treesitter/nvim-treesitter/pull/7392
+(typed_expression
+  "::" @operator)
+
+(unary_typed_expression
+  "::" @operator)
+
 [
   "("
   ")"

tests/query/highlights/julia/test.jl

@@ -2,13 +2,13 @@ function load_data(::Symbol; ::Int) :: Tuple
 # <- @keyword.function
 #        ^ @function.call
 #                 ^ @punctuation.bracket
-#                  ^^ @punctuation.delimiter
+#                  ^^ @operator
 #                    ^ @type.builtin
 #                          ^ @punctuation.delimiter
-#                            ^^ @punctuation.delimiter
+#                            ^^ @operator
 #                              ^^^ @type.builtin
 #                                 ^ @punctuation.bracket
-#                                   ^^ @punctuation.delimiter
+#                                   ^^ @operator
 #                                      ^ @type.builtin
     dataset = CIFAR10(; Tx = Float32, split = split)
 #   ^^^^^^^ @variable