Remove incorrect filter region assumption

Ref https://www.w3.org/TR/SVG11/filters.html

Spec says filter region is not always 100% 100% by default

test/regression.js

@@ -108,7 +108,6 @@ const runTests = async ({ svgFiles }) => {
       // unstable test
       name === 'filters-light-04-f' ||
       // mismatched draft cases
-      name === 'filters-offset-02-b' ||
       name === 'imp-path-01-f' ||
       name === 'interact-pointer-04-f' ||
       name === 'painting-marker-properties-01-f' ||