fix(47256): @deprecated does not work on index signatures

[a-tarasyuk]

Fixes #47256

[DanielRosenwasser]

@typescript-bot pack this

[typescript-bot]

Heya @DanielRosenwasser, I've started to run the tarball bundle task on this PR at c4a5747. You can monitor the build here.

[typescript-bot]

Hey @DanielRosenwasser, I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/117346/artifacts?artifactName=tgz&fileId=9CB93B325A6DA081DFA23E8AC822DD7D7E42D1CA33AA04A030B2F3F579CAB1F702&fileName=/typescript-4.6.0-insiders.20220113.tgz"
    }
}

and then running npm install.

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There is also a playground for this build and an npm module you can use via "typescript": "npm:@typescript-deploys/pr-build@4.6.0-pr-47400-2".;