Scheme: Remove blend() matching

Was integrated into the core CSS syntax with sublimehq/Packages#2700.

Doesn't support our nested modified `var` highlighting, but that can be
tackled later with a custom syntax that extends CSS.

Closes #324

Package/Sublime Text Color Scheme/Sublime Text Color Scheme.sublime-syntax

@@ -381,7 +381,6 @@ contexts:
     # https://www.sublimetext.com/docs/minihtml.html#css:ver-dev
     - include: color-var-function
     - include: color-min-contrast-function
-    - include: color-blend-function
     # Adjusters may be used directly (#327)
     - include: CSS.sublime-syntax#color-adjuster-functions
 
@@ -408,27 +407,6 @@ contexts:
         - match: (?=")
           pop: true
 
-  color-blend-function:
-    # Different syntax
-    - match: \b(?i:blenda?)(?=\()
-      scope: meta.function-call.identifier.css support.function.color.css
-      push:
-        - meta_scope: meta.function-call.blend.css
-        - match: \(
-          scope: punctuation.section.group.begin.css
-          set:
-            - meta_scope: meta.function-call.arguments.css meta.group.css
-            - match: (?=")  # embed this here so we don't have to "with_prototype"
-              pop: true
-            - include: color-var-function
-            - include: CSS.sublime-syntax#function-arguments-common  # matches 'var' function
-            - include: CSS.sublime-syntax#color-values
-            - include: CSS.sublime-syntax#percentage-constants
-            - match: \b(?i:rgb|hsl|hwb)\b
-              scope: keyword.other.color-space.css
-        - match: (?=")
-          pop: true
-
   color-var-function:
     # Supports identifiers without leading `--`
     - match: \b(?i:var)(?=\()

Package/Sublime Text Color Scheme/syntax_test_colorscheme.json

@@ -140,6 +140,11 @@
 //                         ^^^ support.function.var.css
 //                             ^^^^^^^^^^^^^^^^^ variable.other.sublime-color-scheme
 //                                               ^ punctuation.definition.string.end.json
+            "foreground": "blend(hsl(219, 10%, 6%) 50%)",
+//                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ meta.mapping.value.json string.quoted.double.json meta.color.sublime-color-scheme
+//                        ^ punctuation.definition.string.begin.json
+//                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ source.css-color meta.function-call
+//                               ^^^^^^^^^^^^^^^^^ meta.function-call meta.function-call
             "foreground": "color(var(color_radical_red) tint(20%))",
 //                                   ^^^^^^^^^^^^^^^^^ variable.other.sublime-color-scheme
             "foreground": "#F8F8F0",