Inventory fails to prohibit standard library access prior to initialization of Rust standard library runtime

Summary

Affected versions allow arbitrary caller-provided code to execute before the lifetime of `main`. If the caller-provided code accesses particular pieces of the standard library that require an initialized Rust runtime, such as `std::io` or `std::thread`, these may not behave as documented. Panics are likely; UB is possible. The flaw was corrected by enforcing that only code written within the `inventory` crate, which is guaranteed not to access runtime-dependent parts of the standard library, runs before `main`. Caller-provided code is restricted to running at compile time.