Update gatekeeper to 3.8

Package Merge Request

Package Changes

Update OPA Gatekeeper to 3.8 as well as update from upstream chart

Package MR

https://repo1.dso.mil/platform-one/big-bang/apps/core/policy/-/merge_requests/139

For Issue

Closes https://repo1.dso.mil/platform-one/big-bang/apps/core/policy/-/issues/156

BB Processes

Add labels for affected packages so that they are deployed in CI as well as a status label:

added gatekeeper label

assigned to @rob.ferguson

Closing this MR as one one auto generated when the tag was created here: https://repo1.dso.mil/platform-one/big-bang/bigbang/-/merge_requests/1659

closed