Add support for luarocks spec

Hello Scancode Team,

I wanted to generate SBOM for my kong source code using scancode tool.
But the output generated from the tool contains very few component (may be just 2 or 3). while the jsonpp output contains so many entries(it also scans all the lua file).

URL of the source code: https://github.com/Kong/kong/tree/3.3.0
Command which I used to scan the souce code and generate sbom:

```
scancode -n 12 -ip kong/ --json-pp kong-3.3.0.json --cyclonedx kong-3.3.0_cdxSBOM.json --classify --summary --consolidate --full-root --mark-source
```

For the reference, I am attaching the SBOM as well as the jsonpp output.

[kong-3.3.0.txt](https://github.com/nexB/scancode-toolkit/files/12748494/kong-3.3.0.txt)
[kong-3.3.0_cdxSBOM.txt](https://github.com/nexB/scancode-toolkit/files/12748495/kong-3.3.0_cdxSBOM.txt)

Can you please have a look on this issue.