Remove zoom-with-sign-function.html from the webcompat focus area.

This fixes web-platform-tests/interop#939

Author: dholbert

css/css-viewport/zoom/META.yml

@@ -33,7 +33,6 @@ links:
         - test: svg.html
         - test: textarea-very-small-zoom-crash.html
         - test: word-spacing.html
-        - test: zoom-with-sign-function.html
         - test: stroke.html
         - test: svg-path.html
         - test: svg-viewBox.html