Convert @emotion/react's source code to TypeScript (#3281)

* Convert `@emotion/react`'s source code to TypeScript

* add changeset

* limit `package.json['files']`

* fixed type issue

* try `esModuleInterop`

* add required cast

* use `resolveJsonModule` too

* fixed extra things

* fixed a silly mistake

* one extra thing

* fixed type error

* try building before running dtslint

* fixed import

* try to bump tested TS versions

* add extra ts-ignore

* make sure the ts-ignore is above the problematic line

* rewrite tests to stop relying on implementation detail

* fixed type error

* corrext tests

* fixed entrypoints types

Author: Andarist

.changeset/rotten-baboons-knock.md

@@ -0,0 +1,5 @@
+---
+'@emotion/react': minor
+---
+
+Source code has been migrated to TypeScript. From now on type declarations will be emitted based on that, instead of being hand-written.

.github/workflows/main.yml

@@ -88,5 +88,8 @@ jobs:
       - uses: actions/checkout@v3
       - uses: ./.github/actions/ci-setup
 
+      - name: build
+        run: yarn build
+
       - name: dtslint
         run: yarn test:typescript