Allow overriding fzf_opts header for git_commits

[stuckinsnow]

Hello, I have noticed fzf_opts doesn't work when the picker is set to git_commits i.e. it shows the default press ctrl-y to copy commit hash in the header. It would be great if we were able to change this.

It's specifically with the git commit picker, for example -- https://github.com/stuckinsnow/gitty/blob/main/lua/gitty/providers/github-compare/comparison-utils.lua#L169-L169

I am able to circumvent this by opening fzf differently, but then I have to write a custom [preview] feature. So I thought I would request it as a feature.

If this is an error on my part, my bad!

[ibhagwan]

If you don’t need this action set it to false, the header will go away too:

FzfLua git_commits actions.ctrl-y=false