merge: remove no longer required ACTION_GET_OTHER_AND_STORE In 1b8fd4af33189c84feadb47c74d659ec31cde3b9 I (ab)used merge actions to pass info from manifestmerge() to applyupdates() and store info in mergestate. In previous patches, we introduced a separate return value from manifestmerge() and calculateupdates() and an argument to applyupdates() which achieved the same thing. Let's remove this no longer required messy code. Differential Revision: https://phab.mercurial-scm.org/D8744