kmod-parser: duplicate module filename causes failure

[ddiss]

I hit this on a debian aarch64 image:

aarch64-ci:~/rapido$ ./rapido cut -B simple-example
no rapido.conf, using defaults
Error: Custom { kind: InvalidInput, error: "Failed to load modules.builtin: duplicate entry: \"kernel/drivers/perf/arm-cci.ko\"" }

aarch64-ci:~/rapido$ grep arm-cci /usr/lib/modules/$(uname -r)/*
grep: /usr/lib/modules/6.12.105+deb13-cloud-arm64/kernel: Is a directory
/usr/lib/modules/6.12.105+deb13-cloud-arm64/modules.builtin:kernel/drivers/bus/arm-cci.ko
/usr/lib/modules/6.12.105+deb13-cloud-arm64/modules.builtin:kernel/drivers/perf/arm-cci.ko

I'm not sure how we should handle duplicate module names like this (I didn't think there were any), but I suppose we should look at how regular kmod behaves.