[clangd] Adapt Inlay Hint support for Deducing This (#68177)

This is a follow-up for D140828, making Clangd omit the explicit object
parameter in a call to member function with Deducing This.

Given that the parent patch is still in its infancy and might undergo
several reverting-relanding processes, one can feel free to revert this
if encountering any CI failure. And please let me know if I should alter
anything.