fix(npm-groovy-lint): diagnostics not parsed

[mosheavni]

I was getting this error:

[DEBUG Wed Dec 25 11:39:06 2024] /Users/mavni/Repos/none-ls.nvim/lua/null-ls/helpers/generator_factory.lua:352: spawning command "npm-groovy-lint" at /Users/mavni/Repos/shared-libraries with args { "-o", "json", "-" }
[TRACE Wed Dec 25 11:39:06 2024] /Users/mavni/Repos/none-ls.nvim/lua/null-ls/helpers/generator_factory.lua:236: error output: Parse options error: EAGAIN: resource temporarily unavailable, read

[TRACE Wed Dec 25 11:39:06 2024] /Users/mavni/Repos/none-ls.nvim/lua/null-ls/helpers/generator_factory.lua:237: output: nil
[TRACE Wed Dec 25 11:39:06 2024] /Users/mavni/Repos/none-ls.nvim/lua/null-ls/helpers/generator_factory.lua:247: ignoring stderr due to generator options
[TRACE Wed Dec 25 11:39:06 2024] /Users/mavni/Repos/none-ls.nvim/lua/null-ls/diagnostics.lua:185: received diagnostics from source 11
[TRACE Wed Dec 25 11:39:06 2024] /Users/mavni/Repos/none-ls.nvim/lua/null-ls/diagnostics.lua:186: {}

maybe because the stdin was too heavy, I was able to fix that with writing to a temp file.
then, I had to change the on_output to find the key of the files table and not assume it's "1"

anyway here's the before:

and here's the after:

One more thing. when developing a Jenkinsfile, we import a library our system doesn't recognize so base on this:
nvuillam/npm-groovy-lint#422 (comment)
we should add the flag --no-parse in this case.