'annotate' macro address is incorrect in conformance/system_macros/annotate.ion

[tgregg]

Annotate has system macro address 8: https://amazon-ion.github.io/ion-docs/books/ion-1-1/modules/system_module.html

In https://github.com/amazon-ion/ion-tests/blob/main/conformance/system_macros/annotate.ion , system macro address 2 is used.

(ion_1_1 "annotate can be invoked"
         (each "in text with an unqualified macro name"
               (text " (:annotate (::) 0) ")
               "in text with an unqualified macro address"
               (text " (:2 (::) 0) ")
               "in text with a qualified macro name"
               (text " (:$ion::annotate (::) 0) ")
               "in text using qualified system macro address 2"
               (text " (:$ion::2 (::) 0) ")
               "in binary using system macro address 2"
               (binary "EF 02 00 60")
               "in binary with a user macro address"
               (binary "02 00 60")
               (produces 0)))