feat: handle bun projects in apheleia-npx

[inkpot-monkey]

The apheleia-npx script now checks for bun projects and handles them correctly by using the installed bun bin exec the command.

[inkpot-monkey]

Not sure why the formatter test is failing, as this change shouldn't have any impact on previous formatters.

Would it be useful for me to add in a test case here for bun?

[raxod502]

Could be that a newer version of Prettier formats differently by default, breaking the test, or a bug in Prettier being able to find configuration files correctly. Probably the former. I can look into it in a bit.

A new test would be great although the test framework might need to be tweaked a bit to write a good test for this. That is also something I can look at in a bit.

Or you can have a go if you feel up to it earlier.