multer@v1.4.5-lts.1 failures

Hi @linusu I noticed you're listed as maintainer for multer so I'd like to bring to your attention that multer@v1.4.5-lts.1 tests have been failing inconsistently across different systems on v18.x. Feel free to loop in more contributors that you think may help.

I can reproduce the test issue on my macOS with node v18.18.0.
On this pastebin you can clearly see that the first run generates an error but the second one works fine without any config change.

To temporary address this issue, I created #998 to set the test flaky on macOS but would be great to fix the underlying issue (if present)

Here are a few failed citgm runs for reference:
https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/3298/testReport/

As you can see on this run multer is failing on three different nodes. Right now I'm not able to test on other architectures, but can be that the module is flaky also on these platforms

Start with the linked citgm-smoker test report and reproduce the intermittent failure on macOS with Node v18.18.0, comparing the first and second runs described in the issue and the pastebin output. Check the temporary workaround in #998; done means identifying and fixing the underlying flaky test behavior and confirming the relevant citgm runs pass consistently.