I would like a pony 🐴 and a unicorn 🦄. I would also like to drop support for targeting Windows Vista and Server 2008 (Vista's server counterpart, distinct from Server 2008 R2 which was Win7's server counterpart).

According to Wikipedia, extended support for Vista ended in April 2017, and security updates for Server 2008 ended in January 2020.

The only part of the STL that cares about the difference between Vista and Win7 is the mutex / condition_variable machinery. While the v19 ABI restricts us from making data structures significantly smaller and cleaner, we could still improve the code by unconditionally assuming that the target OS is Win7+ (benefiting all users). It might even be possible to make mutex's constructor constexpr, which has been a longstanding conformance issue (see #2285).

I think this decision might already have been made at the VS level, so we just need to confirm things with our bosses and boss-like entities. Visual Studio 2022 Platform Targeting and Compatibility says:

Build Apps that Run on Windows Clients

Windows client version	Using Tools for Native and Managed Classic Windows Desktop Development	Using Tools for UWP App Development
[...]	[...]	[...]
Windows 7	Yes	Not applicable
Windows Vista	No	Not applicable
Windows XP	No	Not applicable

This seems to clearly say that the VS 2022 toolset cannot be used to build apps targeting Vista (but of course the VS 2019 and earlier toolsets remain available to install).