fix: fix types file path cannot be resolved, remove typesVersions field

[zthxxx]

Will cause an error with eslint-import-resolver-typescript, due to missing types files.

And make the field typesVersions is meaningless, because it doesn't support ts version < 4.2 at rxjs@7.

[zthxxx]

@kwonoj

[cartant]

#6466 (comment)

[cartant]

I'm closing this because the resolution implementation to which you've linked in eslint-import-resolver-typescript is incorrect - see this explanation from a TypeScript contributor. As outlined in the package.json, RxJS v7 requires TypeScript 4.2 or greater. The incorrect resolution in eslint-import-resolver-typescript is not something for which RxJS is responsible.

[zthxxx]

@cartant May I ask why need typesVersions field, and what's the use of "dist/types/*"? What's helpful of it rather than "types": "./dist/types/index.d.ts"?

[cartant]

Two reasons:

• it's a mechanism through which it can be made clear that 4.2 is the minimum-supported version of TypeScript for RxJS; and
• it's a mechanism that we could use to update the types - without breaking people - to take advantage of any useful features offered by newer versions of TypeScript. That is, we could add an additional entry in typesVersions. In v7, the types were simplified quite a bit, but there are still some that are complicated and I like to hope that future versions of TS will offer features that could be used to further simplify them.