Fix static linking

[sandydoo]

Re-enables static linking when static-link is enabled on its own, without any other packaging features, like use-pkgconfig. This fixes a regression introduced in #1352.

[Cobrand]

Thanks! Before merging this I need to fix the pipeline, it might take a while before it's merged.

[sandydoo]

A quick way to fix CI is to switch to macos-13, which still uses x86 runners. The new macos-latest is ARM-only.

I'll try to debug the ARM macOS issue.

[sandydoo]

I think the issue is that the video test is not running on the main thread. --test-threads=1 still breaks, but running cargo test --features "..." video works.
We might have to run the tests manually then, without the harness. At least on macOS.