Create post upgrade task function and command to allow renovate runner to bump chart.yaml version

Add a function to post upgrade tasks functions.sh to bump the chart.yaml version and add the command to allowedPostUpgradeCommands. This will then be added to every package renovate.json in this issue https://repo1.dso.mil/platform-one/big-bang/bigbang/-/issues/1110 to automatically bump chart.yaml version in renovate MRs