Deduplicate "Render methods should be pure" warning

[gaearon]

Note: the task is already claimed.

Just saw this in a fiddle that has a nested update bug:

It would be nice to just dedupe them in the first place instead of calling console.error a thousand times.

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Note: the task is already claimed.

[gaearon]

Same for this one:

[imanushree]

I am interested in taking this up. This would be one of my first open source contributions and I am really excited about it :)

[gaearon]

Sounds great! You'll need to search the codebase to find where we fire these two warnings, and then add boolean variables for each. If we fire it once, we set a boolean. Next time we check a boolean before firing it, and skip if the boolean is already set.

[gaearon]

If you have any questions feel free to ping me here.

[gaearon]

Fixed in #11113.