[core] Remove the deprecation rule in tslint

[michaldudak]

The TSLint's deprecation rule is broken, spamming the console with errors like message.trim() is not a function. Indeed the rule's code makes wrong assumptions about what gets returned from the parser.
The fix is theoretically very simple, but since TSLint is no longer maintained, it is not an option.

I tried to replace it with https://github.com/gund/eslint-plugin-deprecation, but it's insanely slow, so it's a no-go.

[mui-bot]

Netlify deploy preview

https://deploy-preview-38087--material-ui.netlify.app/

Bundle size report

No bundle size changes (Toolpad)
No bundle size changes

Generated by 🚫 dangerJS against fe4b374

[oliviertassinari]

MUI X moved away from TSLint: https://github.com/mui/mui-x/blob/e3932b3fc9a3b51bb6fe147c5c894be86254e531/packages/grid/x-data-grid/package.json#L33, I imagine they gave up on this deprecated feature: https://palantir.github.io/tslint/rules/deprecation/.

If we give up on it too here, then nothing would stop us to move away from TSLint?

I have upvoted: microsoft/TypeScript#49433.

[michaldudak]

Our TSLint checks rules defined in https://github.com/microsoft/dtslint/blob/master/dtslint.json.
We'd have to check if equivalent rules exist in ESLint before getting rid of TSLint altogether.