cubicweb #4411354 replace PIL dependency with Pillow [validation pending]

PIL is essentially dead, Pillow replaces it with the same API.

prioritynormal
typetask
done in3.19.5
load0.250
load left0.000
closed by#bf4f5064c7f5 [pkg] Depend on Pillow instead of PIL
patchDepends on Pillow instead of PIL. [applied]