ci/build: Build across different Ubuntu variants

The transition to libusb was tested on a few different Linux distros,
but apparently not Ubuntu 20.04, which contains a slightly older version
of the libusb includes.

Add Ubuntu 20.04 as a CI target to catch more such issues, and for good
measure also add 24.04.

Signed-off-by: Bjorn Andersson <[email protected]>

.github/workflows/build.yml

@@ -9,7 +9,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-latest, macos-latest ]
+        os: [ ubuntu-24.04, ubuntu-22.04, ubuntu-20.04, macos-latest ]
     runs-on: ${{ matrix.os }}
 
     steps: