Gatekeeper remove bigbang overrides

Package Owner Merge Request

Package Changes

• https://repo1.dso.mil/platform-one/big-bang/apps/core/policy/-/merge_requests/91
• https://repo1.dso.mil/platform-one/big-bang/apps/core/policy/-/releases/3.5.1-bb.12

Additional Details

Removes overrides in OPA Gatekeeper that are already included in Big Bang under chart/templates/gatekeeper/values.yaml

Closes https://repo1.dso.mil/platform-one/big-bang/bigbang/-/issues/672