Molybdenum disulphide is your friend.
Pivot ball of clutch release arm needs lubricating...
Put up with it till your clutch is shot & sort it out then...
WD40 will help for a day or so, in the long run it'll make the problem worse, more rapidly.
If you're a lazy bum, & can't be bothered waiting to change theclutch etc...
Use graphite spray with a straw attachment on the end so as not to get any on the friction disc.
Cheers

Adrian.