Re-enable two Linux tests

[cclauss]

Fixes #321

• Fix two failing tests on Linux #321

---

      - if: runner.os == 'Linux'
        run: sudo apt-get install -y libmagic1

sudo apt-get install -y libmagic1
Reading package lists...
Building dependency tree...
Reading state information...
libmagic1 is already the newest version (1:5.41-3ubuntu0.1).
libmagic1 set to manually installed.
0 upgraded, 0 newly installed, 0 to remove and 15 not upgraded.

@ddelange Your review, please.

[ddelange]

libmagic1 is already the newest version (1:5.41-3ubuntu0.1).

I think you'll need 5.44 or newer. At least with 5.45 it's passing: https://github.com/ddelange/python-magic/actions/runs/9189333058/job/25271162839#step:4:13

To install latest libmagic from source, I'm adding add_libmagic.sh in #294.

[cclauss]

Closing in favor of #294 which fixes these tests.

• Build platform-specific wheels containing libmagic #294