[3.13] Fix typo in ElementTree docs (GH-120342) (#120357)

Fix typo in ElementTree docs (GH-120342)
(cherry picked from commit 0335662)

Co-authored-by: naglis <[email protected]>

Author: miss-islington

Doc/library/xml.etree.elementtree.rst

@@ -508,7 +508,7 @@ Functions
    `C14N 2.0 <https://www.w3.org/TR/xml-c14n2/>`_ transformation function.
 
    Canonicalization is a way to normalise XML output in a way that allows
-   byte-by-byte comparisons and digital signatures.  It reduced the freedom
+   byte-by-byte comparisons and digital signatures.  It reduces the freedom
    that XML serializers have and instead generates a more constrained XML
    representation.  The main restrictions regard the placement of namespace
    declarations, the ordering of attributes, and ignorable whitespace.