gh-35868: Minor typo in Category documentation
    
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### 📚 Description

Fixed a typo in which an element object was included in a list of
morphism objects.

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URL: #35868
Reported by: Aram Dermenjian
Reviewer(s): Frédéric Chapoton

Author: Release Manager

src/sage/categories/primer.py

@@ -578,7 +578,7 @@ class implements:
 
 - Group, Monoid, Semigroup, Magma, ...
 - GroupElement, MonoidElement, SemigroupElement, MagmaElement, ...
-- GroupMorphism, SemigroupElement, SemigroupMorphism, MagmaMorphism, ...
+- GroupMorphism, MonoidMorphism, SemigroupMorphism, MagmaMorphism, ...
 
 (and in fact many more as we will see).