Updated fluentbit git tag

Package Merge Request

Package Changes

https://repo1.dso.mil/platform-one/big-bang/apps/core/fluentbit/-/blob/0.21.7-bb.0/CHANGELOG.md

Package MR

https://repo1.dso.mil/platform-one/big-bang/apps/core/fluentbit/-/merge_requests/94

For Issue

Closes https://repo1.dso.mil/big-bang/apps/core/fluentbit/-/issues/56