resources: Address Dart Sass deprecation of global built-in functions

See https://github.com/sass/dart-sass/releases/tag/1.80.0

Fixes #12961

resources/resource_transformers/tocss/sass/helpers_test.go

@@ -0,0 +1,43 @@
+// Copyright 2024 The Hugo Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sass
+
+import (
+	"testing"
+
+	qt "github.com/frankban/quicktest"
+)
+
+func TestIsUnquotedCSSValue(t *testing.T) {
+	c := qt.New(t)
+
+	for _, test := range []struct {
+		in  any
+		out bool
+	}{
+		{"24px", true},
+		{"1.5rem", true},
+		{"10%", true},
+		{"hsl(0, 0%, 100%)", true},
+		{"calc(24px + 36px)", true},
+		{"24xxx", true}, // a false positive.
+		{123, true},
+		{123.12, true},
+		{"#fff", true},
+		{"#ffffff", true},
+		{"#ffffffff", false},
+	} {
+		c.Assert(isTypedCSSValue(test.in), qt.Equals, test.out)
+	}
+}