`pants fix` goal runs formatters, but doesn't respect `[fmt].only` parameter

[pp-gborodin]

`pants fix` goal runs formatters, but doesn't respect `[fmt].only` parameter

[grihabor]

I want to explain my motivation here: I tried using new ruff formatter (pants release 2.20.0dev3) along with ruff checker. It uses the same tool_subsystem = Ruff and therefore the same tool_id = "ruff". This makes it impossible to turn off the ruff formatter, but not the ruff checker.

My first idea was to make pants fix respect [fmt].only parameter, this way I could set [fmt].only=['black'] and run pants fix and it will only run ruff check --fix and not ruff format. But now I'm not sure it's a good idea, because [fmt] is dedicated to the fmt goal, it's not clear why fix goal should respect fmt subsystem. The same logic also applies to lint goal, if fix goal respects [fmt] then lint goal should also respect [fmt], right? It all looks weird, so I think the right solution is to change tool_id for ruff:

class RuffFixRequest(FixTargetsRequest):
    tool_id = 'ruff-check'
    ...

class RuffFormatRequest(FmtTargetsRequest):
    tool_id = 'ruff-format'
    ...

This will solve the issue and keep the current lint/format/fix structure.