[SVG] Make 'paint-order' property inherits

https://bugs.webkit.org/show_bug.cgi?id=260335

Reviewed by Tim Nguyen.

This patch aligns WebKit with Blink / Chromium, Gecko / Firefox and Web-Spec [1].

This PR makes 'paint-order' property to be inherited as per spec.

[1] https://svgwg.org/svg2-draft/painting.html#PaintOrder

* Source/WebCore/css/CSSProperties.json: 'paint-order' to be inherited
* LayoutTests/imported/w3c/web-platform-tests/svg/painting/inheritance-expected.txt: Rebaselined

Canonical link: https://commits.webkit.org/267002@main

LayoutTests/imported/w3c/web-platform-tests/svg/painting/inheritance-expected.txt

@@ -28,7 +28,7 @@ PASS Property marker-mid inherits
 PASS Property marker-end has initial value none
 PASS Property marker-end inherits
 PASS Property paint-order has initial value normal
-FAIL Property paint-order inherits assert_equals: expected "markers stroke" but got "normal"
+PASS Property paint-order inherits
 PASS Property color-interpolation has initial value srgb
 PASS Property color-interpolation inherits
 PASS Property shape-rendering has initial value auto

Source/WebCore/css/CSSProperties.json

@@ -5218,6 +5218,7 @@
             }
         },
         "paint-order": {
+            "inherited": true,
             "codegen-properties": {
                 "converter": "PaintOrder",
                 "parser-function": "consumePaintOrder",