"libmsvcrt-os" was added to the list of excluded libs in binutils in
9d9c67b06c1bf4c4550e3de0eb575c2bfbe96df9 in 2017.
"libucrt" was added in c4a8df19ba0a82aa8dea88d9f72ed9e63cb1fa84 in 2022.
"libucrtapp" isn't in the binutils exclusion list yet, but a patch for
adding it has been submitted. Since
0d403d5dd13ce22c07418058f3b640708992890c in mingw-w64 (in 2020), there's
such a third variant of the UCRT import library available.
Since 18df3e8323dcf9fdfec56b5f12c04a9c723a0931 in 2025, "libpthread" and
"libwinpthread" are also excluded.