Fix typo in UnsatisfiedRequirements exception message

Closes Homebrew/homebrew#42125.

Signed-off-by: Baptiste Fontaine <batifon@yahoo.fr>

Library/Homebrew/exceptions.rb

@@ -123,7 +123,7 @@ class UnsatisfiedRequirements < RuntimeError
     if reqs.length == 1
       super "An unsatisfied requirement failed this build."
     else
-      super "Unsatisified requirements failed this build."
+      super "Unsatisfied requirements failed this build."
     end
   end
 end