A lot of our tests are wrapped in `{}` which serves no purpose, aside from increasing the nesting level and, in some cases, causing confusion. The braces appear to be a leftover from a time when all tests were wrapped in a `function main() {}`. The function declaration was removed in #21053, but the braces remained, presumably because it was easier to search&replace for `function main()`, but not to remove the braces at the same time.
PR Close#52239
`main()` function used to be needed to support dart, since dart
Does not allow top level statements. Since we no longer use dart
The need for `main()` has been removed.
In preparation for `Basel` and standardized way of running tests
we are removing `main()`
PR Close#21053
