Source feature overwritten by suffix

[christios]

https://github.com/CAMeL-Lab/camel_tools/blob/b496501590ee0753eeb3686037fffeb12f4c80d2/camel_tools/morphology/utils.py#L219C33-L222C36

Hello,

In these lines, the complex suffix source feature is overriding that of the stem. This should be excluded as not all stems have source:lex whereas all suffixes currently do, like in Camel Morph where we add Wiki entries with source:wiki.