bump plotly version and edition to 2021 #360

Job	Run time
Rustfmt	13s
Clippy	31s
Build Wasm Examples (wasm-yew-minimal)	25s
Build Examples (3d_charts)	29s
semver	1m 16s
Build Examples (basic_charts)	33s
Tests (ubuntu-latest)	32s
Build Examples (custom_controls)	29s
Tests (windows-latest)	1m 44s
Code Coverage	37s
Build Examples (financial_charts)	31s
Tests (macos-latest)	46s
Build Examples (images)	23s
Build Examples (kaleido)	1m 15s
Build Examples (maps)	29s
Build Examples (ndarray)	29s
Build Examples (scientific_charts)	28s
Build Examples (shapes)	32s
Build Examples (subplots)	31s
	12m 13s

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