Remove Highlight text test case since we have integration and visual …

…tests for this (#165)

test-cases/gutenberg/writing-flow/rich-text-formatting.md

@@ -9,20 +9,6 @@ Have a rich-text based component with content (Paragraph, Heading, Quote, Media
 
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-##### TC001
-
-**Known Issues**
-
-- [Text color selection is not preserved when cursor is placed in the middle of text](https://github.com/WordPress/gutenberg/issues/42714)
-
-### Highlight text without selection
-
-- Without selecting any text tap on the highlight text button (Drop icon) located in the formatting toolbar.
-- Select a color and write some text.
-- Expect to see the newly introduced text with the previously selected color.
-
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-
 ##### TC007
 
 ### Test format detection under the cursor