chore(gem): update bundler and dependencies

[tthvo]

Closes #131

Update bundler version to 2.4.10 (Fedora 38) and other deps.

As for the sass warnings, it is jekyll-sass-converter (3.0.0) (i.e. new sass regulations) and minima incompatibility that caused the issue.

• minima addressed it in latest commits on main. However, no patch release came out for pretty much 3 years now: SASS is deprecating the ability to use a / (slash) for division. jekyll/minima#709
• Workaround by just muting the warnings since we can't really do anything about it: https://sass-lang.com/documentation/js-api/interfaces/options/#quietDeps