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

@@ -122,14 +122,14 @@ install amd64:
   # Native AMD64 on AMD64
     - .ci/integration_tests/build_images qemu-amd64 phosh
   # ARM64 on AMD64
-    - .ci/integration_tests/build_images qemu-aarch64 phosh
+    - .ci/integration_tests/build_images postmarketos-trailblazer phosh
 
 install aarch64:
   extends: .integration
   tags: [arm64]
   script:
   # Native ARM64 on ARM64
-    - .ci/integration_tests/build_images qemu-aarch64 phosh
+    - .ci/integration_tests/build_images postmarketos-trailblazer phosh
   # AMD64 on ARM64
     - .ci/integration_tests/build_images qemu-amd64 phosh