`ffmpeg-static` does not seem to rebuild if the binary already exists at ./ffmpeg

### ffmpeg-static version

5.2.0

### Node.js version

v18.20.3

### operating system and/or environment

MacOS 11.3.1
`@electron-forge`
`electron/universal`

### What happened?

We are using `ffmpeg-static` in a build process which creates a universal Mac build, and it passes `arch` values for both Intel and M1: x64 and arm64. In the finished app build we noticed there was only ever one arch of the ffmpeg binary created. Digging deeper we found that if a binary already exists at `ffmpeg-static/ffmpeg`, it will not be rebuilt:

```
npm rebuild --arch=x64 -f ffmpeg-static
file node_modules/ffmpeg-static/ffmpeg
```
displays correctly "Mach-O 64-bit executable x86_64"
rebuilding for another arch:
```
npm rebuild --arch=arm64 -f ffmpeg-static
file node_modules/ffmpeg-static/ffmpeg
```
still shows "Mach-O 64-bit executable x86_64"
but removing the binary and rebuilding
```
rm node_modules/ffmpeg-static/ffmpeg
npm rebuild --arch=arm64 -f ffmpeg-static
file node_modules/ffmpeg-static/ffmpeg
```
shows correctly "Mach-O 64-bit executable arm64"