[clang-format] Fix incorrect formatting of lambdas inside brace initialisation

[clang-format] Fix incorrect formatting of lambdas inside brace initialisation

Fixes https://github.com/llvm/llvm-project/issues/27146.
Fixes https://github.com/llvm/llvm-project/issues/52943.

Before:

```
namespace ns {

void foo() {
  std::variant<int, double> v;
  std::visit(overloaded{[](auto &&) -> int (*)[] { return nullptr; }}, v);
}

} // namespace ns

int break_me() {
  int x = 42;
  return int{[x = x]() {
    return x;
  }()};
}
```

got formatted as:
```
namespace ns {

void foo() {
  std::variant<int, double> v;
  std::visit(overloaded{[](auto &&) -> int (*)[] { return nullptr;
}
} // namespace ns
, v);
}

} // namespace ns

int break_me() {
  int x = 42;
  return int{[x = x](){return x;
}
()
}
;
}
```

Reviewed By: HazardyKnusperkeks, owenpan

Differential Revision: https://reviews.llvm.org/D116553