.stale-element is no longer used following our conversion to Emotion. This broke our snapshot test. When trying to fix it real quick as part of the snapshot effort, it looks like this test needs to be reviewed in more detail. When converted to data attribute, the test could not find the updated attribute. Looking at it in person I can see the attribute getting updated. Not sure if it's a timing issue etc.

For now, added .stale-element back to Block.tsx.

The snapshot in develop is wrong pending #2553. Breaking out this snapshot fix to unblock rest of codebase.