chore(lint): prefer 'unknown' to 'any', fix lint warnings

[github-actions]

Note

The pull request "chore(lint): prefer 'unknown' to 'any', fix lint warnings" was created by @isaacs but did not reference an issue. Therefore this issue was created for better visibility in external tools like Linear.

Explicitly enable any usage in typescript in:

• dev-packages, since those are largely integration and E2E tests. (This is done with the addition of a dev-packages/.eslintrc.js file.)
• packages/*/test/, since those are all tests. (This is done with a rule override added to the root .eslintrc.js file.)
• Several one-off allowances, generally for vendored types from third party sources, and cases involving method overwriting that TypeScript can't follow. (These are done with file/line overrides, explicit as casting, and adding type inference to the isInstanceOf method.)

In other places (ie, in exported production code paths), replace any with unknown, and upgrade the @typescript/no-explicit-any lint rule to an error.

This silences a lot of eslint warnings that were habitually ignored, and encourages us to not opt out of strict type safety in our exported code.

[linear]

JS-1296