Mentioned by @stickies-v. The CMake configure currently outputs that MSVC builds are using ccache, i.e (https://github.com/bitcoin/bitcoin/actions/runs/13063954360/job/36452895056#step:8:2374):

Treat compiler warnings as errors ..... ON
Use ccache for compiling .............. ON

However that's a bug, as MSVC is currently excluded entirely from using ccache: