`cabal` crashes in HLS CI while copying files

**Describe the bug**

`cabal 3.16.{0,1}.0` crashes in the HLS CI ([logs](https://github.com/user-attachments/files/24475272/4_Build.txt))

The error in question:

```
2026-01-07T14:53:53.6355558Z copyFile:atomicCopyFileContents:withReplacementFile:CreateFile "D:\\a\\haskell-language-server\\haskell-language-server\\.\\dist-newstyle\\build\\x86_64-windows\\ghc-9.14.1\\hls-2.12.0.0\\t\\hls-qualify-imported-names-plugin-tests\\build\\hls-qualify-imported-names-plugin-tests\\autogen\\.copyFile-da8b2aac-21ce-4e49-8a1b-8f41d1393bf2.tmp": does not exist (does not exist
```

The same error seems to happen for various other packages with long names and this path is 260 characters long, perhaps an indicator for long path issues?

**To Reproduce**
Steps to reproduce the behavior:

On windows only (and I have not tried reproducing locally, might be a GHA CI only thing):

```
$ cabal-3.16.1.0 build test:hls-alternate-number-format-plugin-tests
```

**Expected behavior**

Should not crash, just like cabal 3.14

**System Information**

Seems to only happen on windows, and I haven't tried reproducing locally.