bump plotly version and edition to 2021 #359

Job	Run time
Clippy	29s
Build Wasm Examples (wasm-yew-minimal)	26s
Code Coverage	34s
Build Examples (3d_charts)	31s
Build Examples (basic_charts)	34s
Rustfmt	14s
semver	3m 32s
Tests (ubuntu-latest)	30s
Build Examples (custom_controls)	29s
Tests (windows-latest)	1m 42s
Build Examples (financial_charts)	31s
Tests (macos-latest)	32s
Build Examples (images)	21s
Build Examples (kaleido)	1m 18s
Build Examples (maps)	31s
Build Examples (ndarray)	30s
Build Examples (scientific_charts)	30s
Build Examples (shapes)	31s
Build Examples (subplots)	28s
	14m 13s

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