bump plotly version and edition to 2021 #376

Job	Run time
Clippy	1m 45s
Rustfmt	11s
Build Wasm Examples (wasm-yew-minimal)	45s
Build Examples (3d_charts)	24s
Code Coverage	1m 51s
semver	1m 20s
Build Examples (basic_charts)	24s
Tests (ubuntu-latest)	2m 55s
Build Examples (custom_controls)	30s
Tests (windows-latest)	6m 4s
Tests (macos-latest)	11m 49s
Build Examples (financial_charts)	23s
Build Examples (images)	37s
Build Examples (kaleido)	1m 9s
Build Examples (maps)	25s
Build Examples (ndarray)	23s
Build Examples (scientific_charts)	25s
Build Examples (shapes)	26s
Build Examples (subplots)	22s
	32m 8s

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