Early on my Sonic had a faint clicking noise during clutch activation. My solution was to spray an industrial quality lubricant on all pivot and contact points on the clutch pedal assembly. I protected the carpet area with some shop towels, and sprayed anything that moves. after the lubricant gelled, I wiped the excess lubricant away. The noise hasn't returned in over a year.
What I used was Kimball Midwest Inter-Lube Penetrating Grease # 80-925
It is a clear, penetrating, lubricant that sprays as a liquid, then soon turns to a gel type grease that clings to vertical surfaces, and works from -30 degrees F to 530 degrees F. I'm not sure where an individual can obtain this product, as it is marketed for industrial/professional use. It also is excellent for door hinges and door latch mechanisms. WD 40 isn't a good long term lubricant solution, as it is more of a penetrant and doesn't leave a heavy enough viscosity lubricant when it evaporates.
Below is a link that describes this product.
https://www.kimballmidwest.com/catalog/CatalogIndex.aspx?p=3578&i=22227