CI cache is not working

[jacobvosmaer]

See this example build.

Note how much time is spent in "Install SWIG" and "Install TagLib" even though those steps are supposed to be cached.

I think our cache-less build is fast enough and I suggest we remove the cache steps from CI config to unclutter it.

[robinst]

Looking at https://github.com/actions/cache/blob/v2/README.md#example-workflow, it seems like we're missing a line like this in the Install SWIG step:

if: steps.cache-swig.outputs.cache-hit != 'true'

Same for the Install TagLib step. Do you want to try that first, before removing them?