[Impeller] Remove duplicate code in 'TiledTextureContents'

[ColdPaleLight]

It is a duplicate of the following line of code.

engine/impeller/entity/contents/tiled_texture_contents.cc

Line 81 in 2ac9c73

cmd.pipeline = renderer.GetTiledTexturePipeline(options);

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[flutter-dashboard]

It looks like this pull request may not have tests. Please make sure to add tests before merging. If you need an exemption to this rule, contact Hixie on the #hackers channel in Chat (don't just cc him here, he won't see it! He's on Discord!).

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