Doesn't function for pixel 4a or any devices without a vendor_boot.img

I wouldn't be surprised if this process is just too tailor-made for the post 4a devices that this is just not possible. Currently trying to publish a build for `sunfish` gives this error: ``` [INFO] Unpacking OTA: .tmp/sunfish-ota_update-2025012701.zip 0.000s ERROR Invalid partitions: vendor_boot Stack backtrace: 0: <unknown> 1: <unknown> 2: <unknown> 3: <unknown> 4: <unknown> 5: <unknown> 6: <unknown> 7: <unknown> 8: <unknown> 9: <unknown> 10: <unknown> [ERROR] Failed to patch OTA Traceback (most recent call last): File "/home/runner/work/PixeneOS/PixeneOS/.tmp/tools/my-avbroot-setup/patch.py", line 340, in main run(args, Path(temp_dir)) File "/home/runner/work/PixeneOS/PixeneOS/.tmp/tools/my-avbroot-setup/patch.py", line 231, in run external.unpack_ota(args.input, images_dir, need_boot_fs | need_ext_fs) File "/home/runner/work/PixeneOS/PixeneOS/.tmp/tools/my-avbroot-setup/lib/external.py", line 53, in unpack_ota subprocess.check_call(cmd) File "/opt/hostedtoolcache/Python/3.12.11/x64/lib/python3.12/subprocess.py", line 413, in check_call raise CalledProcessError(retcode, cmd) subprocess.CalledProcessError: Command '['avbroot', 'ota', 'extract', '--input', PosixPath('.tmp/sunfish-ota_update-2025012701.zip'), '--directory', PosixPath('/tmp/tmpkk3tr1ja/images'), '--partition', 'system', '--partition', 'vendor', '--partition', 'vendor_boot']' returned non-zero exit status 1. ```