Don't run mode hooks in eglot--format-markup

[xuchunyang]

Since we want only the syntax highlight provided by the major mode, it makes sense to ignore user's customization functions on the major mode's hook.

[joaotavora]

Makes sense indeed. Do you have copyright assignment to the FSF?

[xuchunyang]

I signed the copyright assignment for the Emacs project some years ago, but I've never needed it, and I am not sure if it is still working.

[joaotavora]

I believe it is: I am not sure if it is still working.

Hmmm. I don't think it has an expiration date. The patch is small enough to go in regardless, so, on the safe side, i added a "Copyright-paperwork-exempt: yes" line.

Thanks!