[temp.inst] Fix typo 'the the'.

Author: zygoloid

source/templates.tex

@@ -5812,7 +5812,7 @@
 of a template specialization or member function
 are not instantiated along with the specialization or function itself,
 even for a member function of a local class;
-substitution into the the atomic constraints formed from them is instead performed
+substitution into the atomic constraints formed from them is instead performed
 as specified in \ref{temp.constr.decl} and \ref{temp.constr.atomic}
 when determining whether the constraints are satisfied.
 \begin{note}