Philipp Spiess 94a3cff687
Fix PostCSS watcher warnings on Windows (#15321)
Resolves #15320
Resolves #15175

Turns out that the postcss file watcher does not like our Unix based
paths and will print a warning about them. This fixes the issue by
calling `path.resolve()` to convert it back to a Windows-style absolute
path if necessary.

## Test Plan

Tested on Windows with a new Next.js 14 project. Ensured that file
reloads also still work (changes to the `tsx` file are picked up
correctly). Also ensure that the CI runs on Windows.

### Before

<img width="1178" alt="Screenshot 2024-12-06 at 13 12 23"
src="https://github.com/user-attachments/assets/70c1fe45-6983-4fb4-9889-716a0cbef03a">

### After

<img width="1196" alt="Screenshot 2024-12-06 at 13 23 24"
src="https://github.com/user-attachments/assets/0b9e3ff7-c5b6-4ccb-85a9-e7ba7aee355a">
2024-12-09 10:44:25 +01:00
..