Change vote duration to at least 72 hours (#933)

Updated voting duration to a minimum of 72 hours.

Author: pjfanning

.github/workflows/stage-release-candidate.yml

@@ -300,7 +300,7 @@ jobs:
           The VOTE will pass if we have more positive votes than negative votes
           and there must be a minimum of 3 approvals from Pekko PMC members.
           Anyone voting in favour of the release, could you please provide a list of the checks you have done?
-          The vote will be left open until [VOTE_ENDS_UTC].
+          The vote will be left open for at least 72hrs.
           
           [ ] +1 approve
           [ ] +0 no opinion