Remove block editor assets from the front end in Twenty Twenty-One

[sabernhardt]

Checks whether is_admin() before adding scripts and styles on 'enqueue_block_assets' action in both Twenty_Twenty_One_Custom_Colors and Twenty_Twenty_One_Dark_Mode.

Trac 60111

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[mukeshpanchal27]

Thanks @sabernhardt, The changes make sense to me.

[mukeshpanchal27]

@sabernhardt Does this PR fully resolve the issue for the ticket, or is there anything still pending? I see there are two other PRs are those still needed, or can we close them if they’re no longer required?

[sabernhardt]

@mukeshpanchal27 This PR should resolve the frontend issues for ticket 60111, though it might be worth adding the enqueue_block_editor_assets fallback used in Twenty Twenty.

As for the other two PRs:

• 5795 was intended for a different ticket.
• 9083 addressed the dark mode scripts on the frontend, taking a very different direction.

[SergeyBiryukov]

Thanks for the PR! Merged in r61471.