Remove libuv
I see that some recently added uses of libuv have been reverted (e.g. bcbb212d). Please consider fully removing your remaining uses of libuv. I see that a request to build without libuv was previously made in #20482 (closed).
The libuv project will only support OS versions that are currently supported the OS vendor. They may accept patches to fix problems with older OS versions but they will not fix them themselves and will not keep bug reports about them open, limiting the discoverability of such issues (e.g. https://github.com/libuv/libuv/issues/4204), and they also actively remove existing workarounds for older OS versions (e.g. https://github.com/libuv/libuv/commit/737f4f953fa908863c3492e6c6a1188acb58370c).
This behavior of the libuv developers is contrary to what I hope are the goals of the cmake project: to be a tool that can be used to build software. It should not be cmake's business to dictate to those other software projects what OS versions they can support.
Users are not always able to update to the latest OS. They may have mission-critical software that is not compatible with a new OS version. Or their computer, which is otherwise fully functional, may have been declared by the OS vendor to be incompatible with the latest OS. There is no reason why this should prevent the user from installing other software that works on that OS.
The cmake project currently publishes binaries that it claims work on OS X 10.10 and later, presumably because there are users who want to use it on old macOS versions. If these binaries were built using a current version of libuv which no longer supports macOS 10.x, then this claim may not be accurate. If these binaries were built using an old version of libuv dating back to a time when OS X 10.10 was still supported by Apple, then they may contain bugs or security issues that have been fixed in later versions of libuv.