evolve: mark new hash-salting extras keys as uninteresting for effect flag The user doesn't care if the `evolve_source_local`/`evolve_source_other` values in the extras changed, so this patch adds them to the blacklist that already exists for that purpose. This should also fix the flakiness we've seen in some tests. The flakiness seemed to stem from `mercurial.obsutil.geteffectflag()` not sorting extras keys. That means we ran into it relatively often for the `evolve_source_local`/`evolve_source_other` keys because there were two of them. That sorting bug should be fixed upstream.

# setup config and various utility to test new heads checks on push

. $TESTDIR/testlib/common.sh

cat >> $HGRCPATH <<EOF
[ui]
# simpler log output
logtemplate ="{node|short} ({phase}): {desc}\n"

[phases]
# non publishing server
publish=False

[extensions]
# we need to strip some changeset for some test cases
strip=
evolve=
EOF

setuprepos() {
    echo creating basic server and client repo
    hg init server
    cd server
    mkcommit root
    hg phase --public .
    mkcommit A0
    cd ..
    hg clone server client
}