parcagpu embeds a parca-dev/proton fork as a vendored source dependency.
It contains parcagpu-specific modifications, and parcagpu uses it to
build Proton CUDA/CUPTI shim sources directly into libparcagpucupti.so.
There is no external Proton library / API suitable for packaging as a
separate dependency, so the source vendors the exact upstream proton
revision used by parcagpu.

test/pc_sample_toy.cubin is used only in upstream testing and is a
prebuilt binary, so it is excluded from the source package.
