CI: Extend integration testing

Refactor the integration test script to support running a variety of tests, and add CI jobs for them.

We might want to combine some of these jobs, or otherwise adjust things, but this was minimal effort to add and should improve our test coverage a bit.

.gitlab-ci.yml

@@ -103,6 +103,16 @@ pytest:
     - apk upgrade -U
     - apk add doas git losetup python3 openssl
     - echo "permit nopass build" > /etc/doas.d/ci-user.conf
+  # Add built packages and images as artifacts so they can be inspected
+  # if needed.
+  after_script:
+    - mkdir packages
+    - mkdir images
+    - mv /home/build/.local/var/pmbootstrap/packages/* packages/
+    - mv /home/build/.local/var/pmbootstrap/chroot_native/home/pmos/rootfs/* images/
+  artifacts:
+    paths: [packages, images]
+    expire_in: 1 week
 
 # Test that we can generate an install rootfs on AMD64 for native
 # and arm64 QEMU targets