Make flycheck dependency optional?

[Icy-Thought]

First of all, I would like to express my gratitude to you for maintaining this awesome fork/project!

Second, I find it rather strange for rustic to install packages that I am not using by default. For example, my Emacs setup currently relies on eglot and flymake, but oddly enough Rustic demands the presence of flycheck even though it was never enabled.

Would it not be saner to have it become an optional dependency instead? For when people want to configure rustic with flycheck instead of flymake.

[jgarte]

I also think that this should be the default behavior.

[CeleritasCelery]

PR's welcome to change this.

[Icy-Thought]

Closing since the PR has been merged.