[exec.scope.concepts] Fix typos

Author: Andreas-Krug

source/exec.tex

@@ -7757,10 +7757,10 @@
 \tcode{static_cast<bool>(assoc)} is \tcode{true}
 if and only if \tcode{assoc} is engaged;
 \item
-no two distinct objects of type \tcode{Assoc} own the same assocation;
+no two distinct objects of type \tcode{Assoc} own the same association;
 \item
 for an object \tcode{assoc} of type \tcode{Assoc},
-destroying \tcode{assoc} releases the assocation owned by \tcode{assoc}, if any;
+destroying \tcode{assoc} releases the association owned by \tcode{assoc}, if any;
 \item
 for an object \tcode{assoc} of type \tcode{Assoc},
 after it is used as the source operand of a move constructor,