feat: Allow flagging of one or the other of abstract noun pairs such as equivalence vs. equivalency and relevance vs relevancy

## Description

English has a set of pairs of abstract nouns in `-ence` / `-ency` or `-ance` / `-ancy` which are synonyms and both correct but one has been more used until very recently with the other currently on the rise. Users should be able to choose which they want used.

## Resources

- [Here's one from Grammarist.com](https://grammarist.com/usage/equivalence-equivalency/)
- [English StackExchange which includes a mini list](https://english.stackexchange.com/questions/97111/difference-between-the-use-of-resilience-and-resiliency)

## Examples

Please provide at least three examples of the grammatical error in real text.

- A powerful flow control component enabling reliability, **resilience** and monitoring for microservices.
- Zuul is a gateway service that provides dynamic routing, monitoring, **resiliency**, security, and more.
- AutoMapper support for updating existing collections by **equivalency**
- **Equivalence** Between Structural Representations and Positional Node Embeddings
- they are showing signs of **incompetence** already all over the place firing the people who working
- ... with this backdrop of ... **incompetency** Cuts all the things you were just talking about ...

## Other

I think there are some words which only existed in one form or the other which people have started using in the hitherto nonexistent form. Spellcheck should catch these but they may bear thinking about.

This is another example of the kind of thing that would warrant a two-way setting. Not sure whether a single lint can currently handle both cases, but probably the best way.

I just heard **reluctancy** used and it sounded wrong to me. It's a word that's been pretty much out of use for a couple of decades that has been picked up again in the last few years. At least two orders of magnitude less common that **reluctance**.

- irrelevance vs irrelevancy
- persistence vs persistency
- turbulence vs turbulency
- vibrance vs vibrancy

The issue names no files, tests, or entry points. Start by tracing the existing lint rules and user-settings handling, then determine how paired word preferences are represented. Done means users can choose either form for the listed noun pairs and the checker applies that choice consistently.

Written by the indexing model from the issue text.