layout: Improve sizing for inline SVG (#38603)

The metadata provided by usvg has unreliable sizes. Ignore it, and rely
on the `width`, `height` and `viewBox` attributes instead.

Note that inline SVG with a natural aspect ratio but no natural sizes
should stretch to the containing block. This is left for a follow-up.

Bumps Stylo to https://github.com/servo/stylo/pull/229

Testing: Improves several WPT.

---------

Signed-off-by: Oriol Brufau <obrufau@igalia.com>
Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>
Co-authored-by: Mukilan Thiyagarajan <mukilan@igalia.com>

tests/wpt/meta/css/css-transforms/scale/svg-scale-001.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-001.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-002.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-002.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-003.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-003.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-004.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-004.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-008.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-008.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-009.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-009.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-010.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-010.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-011.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-011.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-012.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-012.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-013.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-013.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-014.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-014.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-015.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-015.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-016.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-016.html]
+  expected: FAIL

tests/wpt/meta/css/css-transforms/scale/svg-scale-017.html.ini

@@ -0,0 +1,2 @@
+[svg-scale-017.html]
+  expected: FAIL