test: cleaning up our jest config (#700)

Author: erunion

jest.config.js

@@ -12,13 +12,6 @@ module.exports = {
   },
   modulePaths: ['<rootDir>'],
   modulePathIgnorePatterns: ['<rootDir>/dist/'],
-  /**
-   * Not sure why, but the non-legacy preset gives us TS compilation errors
-   * since it's not properly reading our testing TS config.
-   * @see {@link https://kulshekhar.github.io/ts-jest/docs/getting-started/presets}
-   * @see {@link https://kulshekhar.github.io/ts-jest/docs/getting-started/options/tsconfig/}
-   */
-  preset: 'ts-jest/presets/js-with-ts-legacy',
   roots: ['<rootDir>'],
   setupFiles: ['./__tests__/setup'],
   setupFilesAfterEnv: ['jest-extended/all'],