CI: Add bootimg analysis integration test

I'm just checking in a random boot image I had on my PC. I'm not sure if we want to do this, but I'm also not sure how to test this code otherwise. We could use unit tests, but that is not as rigorous.

CI is expected to fail until !2466 (merged) has been merged.

.gitlab-ci.yml

@@ -115,6 +115,11 @@ deploy:
     paths: [packages]
     expire_in: 1 week
 
+analyze bootimg:
+  extends: .integration
+  script:
+    - .ci/integration_tests/analyze_bootimg
+
 # Test that we can generate an install rootfs on AMD64 for native
 # and arm64 QEMU targets
 install amd64: